ORCID Profile
0000-0001-7445-699X
Current Organisation
University of New South Wales
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Quantum Physics | Quantum Information, Computation and Communication | Quantum Physics not elsewhere classified | Electronic and Magnetic Properties of Condensed Matter; Superconductivity | Condensed Matter Characterisation Technique Development | Quantum Optics | Optical Physics | Condensed Matter Physics | Mathematical Physics | Microelectronics and Integrated Circuits | Photodetectors, Optical Sensors and Solar Cells | Electrical and Electronic Engineering | Classical Physics not elsewhere classified | Theoretical Physics | Surfaces and Structural Properties of Condensed Matter | Photonics, Optoelectronics and Optical Communications | Nonlinear Optics and Spectroscopy | Condensed Matter Physics—Electronic And Magnetic Properties; | Quantum Optics And Lasers
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in Engineering | Information processing services | National Security | Integrated circuits and devices | Expanding Knowledge in Technology | Other | Solar-Photovoltaic Energy | Network Infrastructure Equipment | Integrated Circuits and Devices | Expanding Knowledge in the Information and Computing Sciences |
Related Links
Publications
A single-atom quantum memory in silicon
Publisher: IOP Publishing
Date: 03-2017
Optimization of a solid-state electron spin qubit using gate set tomography
Publisher: IOP Publishing
Date: 13-10-2016
Engineering local strain for single-atom nuclear acoustic resonance in silicon
Publisher: AIP Publishing
Date: 25-10-2021
DOI: 10.1063/5.0069305
Abstract: Mechanical strain plays a key role in the physics and operation of nanoscale semiconductor systems, including quantum dots and single-dopant devices. Here, we describe the design of a nanoelectronic device, where a single nuclear spin is coherently controlled via nuclear acoustic resonance (NAR) through the local application of dynamical strain. The strain drives spin transitions by modulating the nuclear quadrupole interaction. We adopt an AlN piezoelectric actuator compatible with standard silicon metal–oxide–semiconductor processing and optimize the device layout to maximize the NAR drive. We predict NAR Rabi frequencies of order 200 Hz for a single 123Sb nucleus in a wide region of the device. Spin transitions driven directly by electric fields are suppressed in the center of the device, allowing the observation of pure NAR. Using electric field gradient-elastic tensors calculated by the density-functional theory, we extend our predictions to other high-spin group-V donors in silicon and to the isoelectronic 73Ge atom.
Low-temperature NMR study of quantum tunneling of magnetization in the molecular magnet Mn12-ac
Publisher: Elsevier BV
Date: 05-2004
Radio frequency readout of electrically detected magnetic resonance in phosphorus-doped silicon MOSFETs
Publisher: IEEE
Date: 12-2010
Automated and versatile SQUID magnetometer for the measurement of materials properties at millikelvin temperatures
Publisher: AIP Publishing
Date: 05-01-2005
DOI: 10.1063/1.1841831
Abstract: We present the design and construction of a SQUID-based magnetometer for operation down to temperatures T≃10mK, while retaining the compatibility with the s le holders typically used in commercial SQUID magnetometers. The system is based on a dc-SQUID coupled to a second-order gradiometer. The s le is placed inside the plastic mixing chamber of a dilution refrigerator and is thermalized directly by the He3 flow. To measure the magnetic moment, the s le is moved through the gradiometer coils by lifting the whole dilution refrigerator insert. A home-developed software provides full automation and an easy user interface.
On-demand electrical control of spin qubits
Publisher: Springer Science and Business Media LLC
Date: 12-01-2023
Long-Range Ferromagnetic Dipolar Ordering of High-Spin Molecular Clusters
Publisher: American Physical Society (APS)
Date: 10-01-2003
Single-spin qubits in isotopically enriched silicon at low magnetic field
Publisher: Springer Science and Business Media LLC
Date: 03-12-2019
DOI: 10.1038/S41467-019-13416-7
Abstract: Single-electron spin qubits employ magnetic fields on the order of 1 Tesla or above to enable quantum state readout via spin-dependent-tunnelling. This requires demanding microwave engineering for coherent spin resonance control, which limits the prospects for large scale multi-qubit systems. Alternatively, singlet-triplet readout enables high-fidelity spin-state measurements in much lower magnetic fields, without the need for reservoirs. Here, we demonstrate low-field operation of metal-oxide-silicon quantum dot qubits by combining coherent single-spin control with high-fidelity, single-shot, Pauli-spin-blockade-based ST readout. We discover that the qubits decohere faster at low magnetic fields with $${T}_{2}^{\\,\\text{Rabi}\\,}=18.6$$ T 2 Rabi = 18.6 μs and $${T}_{2}^{* }=1.4$$ T 2 * = 1.4 μs at 150 mT. Their coherence is limited by spin flips of residual 29 Si nuclei in the isotopically enriched 28 Si host material, which occur more frequently at lower fields. Our finding indicates that new trade-offs will be required to ensure the frequency stabilization of spin qubits, and highlights the importance of isotopic enrichment of device substrates for the realization of a scalable silicon-based quantum processor.
Single-shot readout of an electron spin in silicon
Publisher: Springer Science and Business Media LLC
Date: 26-09-2010
DOI: 10.1038/NATURE09392
Abstract: The size of silicon transistors used in microelectronic devices is shrinking to the level at which quantum effects become important. Although this presents a significant challenge for the further scaling of microprocessors, it provides the potential for radical innovations in the form of spin-based quantum computers and spintronic devices. An electron spin in silicon can represent a well-isolated quantum bit with long coherence times because of the weak spin-orbit coupling and the possibility of eliminating nuclear spins from the bulk crystal. However, the control of single electrons in silicon has proved challenging, and so far the observation and manipulation of a single spin has been impossible. Here we report the demonstration of single-shot, time-resolved readout of an electron spin in silicon. This has been performed in a device consisting of implanted phosphorus donors coupled to a metal-oxide-semiconductor single-electron transistor-compatible with current microelectronic technology. We observed a spin lifetime of ∼6 seconds at a magnetic field of 1.5 tesla, and achieved a spin readout fidelity better than 90 per cent. High-fidelity single-shot spin readout in silicon opens the way to the development of a new generation of quantum computing and spintronic devices, built using the most important material in the semiconductor industry.
Semiconductor qubits in practice
Publisher: Springer Science and Business Media LLC
Date: 19-02-2021
Magnetic dipolar ordering and relaxation in the high-spin molecular cluster compoundMn<
Publisher: American Physical Society (APS)
Date: 05-04-2006
Robust electric dipole transition at microwave frequencies for nuclear spin qubits in silicon
Publisher: American Physical Society (APS)
Date: 30-08-2018
Beating the Thermal Limit of Qubit Initialization with a Bayesian Maxwell’s Demon
Publisher: American Physical Society (APS)
Date: 25-10-2022
Coherent Control of a SingleSi
Publisher:
American Physical Society (APS)
Date:
09-12-2014
Publisher: American Physical Society (APS)
Date: 09-12-2014
Spin thermometry and spin relaxation of optically detected
Cr 3
Publisher:
American Physical Society (APS)
Date:
25-09-2020
Publisher: American Physical Society (APS)
Date: 25-09-2020
Electron Spin Decoherence in Isotope-Enriched Silicon
Publisher: American Physical Society (APS)
Date: 27-10-2010
Fidelity benchmarks for two-qubit gates in silicon
Publisher: Springer Science and Business Media LLC
Date: 05-2019
DOI: 10.1038/S41586-019-1197-0
Abstract: Universal quantum computation will require qubit technology based on a scalable platform
ELECTRON-PHONON COUPLING ORIGIN OF THE RESISTIVITY IN YNi2B2C SINGLE CRYSTALS
Publisher: World Scientific Pub Co Pte Lt
Date: 30-10-2000
DOI: 10.1142/S0217979200002983
Abstract: Resistivity measurements from 4.2 K up to 300 K were made on YNi 2 B 2 C single crystals with T c = 15.5 K . The resulting ρ(T) curve shows a perfect Bloch-Grüneisen (BG) behavior, with a very small residual resistivity which indicates the low impurity content and the high cristallographic quality of the s les. The value λ tr = 0.53 for the transport electron-phonon coupling constant was obtained by using the high-temperature constant value of d ρ/ d T and the plasma frequency reported in literature. The BG expression for the phononic part of the resistivity ρ ph (T) was then used to fit the data in the whole temperature range, by approximating [Formula: see text] with the experimental phonon spectral density G(Ω) multiplied by a two-step weighting function to be determined by the fit. The resulting fitting curve perfectly agrees with the experimental points. We also solved the real-axis Eliashberg equations in both s- and d-wave symmetries under the approximation [Formula: see text]. We found that the value of λ tr here determined in single-band approximation is quite compatible with T c and the gap Δ experimentally observed. Finally, we calculated the normalized tunneling conductance, whose comparison with break-junction tunnel data gives indication of the possible s-wave symmetry for the order parameter in YNi 2 B 2 C .
Atoms and circuits unite in silicon
Publisher: Springer Science and Business Media LLC
Date: 04-2013
Gate-based single-shot readout of spins in silicon
Publisher: Springer Science and Business Media LLC
Date: 11-03-2019
DOI: 10.1038/S41565-019-0400-7
Abstract: Electron spins in silicon quantum dots provide a promising route towards realizing the large number of coupled qubits required for a useful quantum processor
Quantum-coherent nanoscience.
Publisher: Springer Science and Business Media LLC
Date: 29-11-2021
DOI: 10.1038/S41565-021-00994-1
Abstract: For the past three decades nanoscience has widely affected many areas in physics, chemistry and engineering, and has led to numerous fundamental discoveries, as well as applications and products. Concurrently, quantum science and technology has developed into a cross-disciplinary research endeavour connecting these same areas and holds burgeoning commercial promise. Although quantum physics dictates the behaviour of nanoscale objects, quantum coherence, which is central to quantum information, communication and sensing, has not played an explicit role in much of nanoscience. This Review describes fundamental principles and practical applications of quantum coherence in nanoscale systems, a research area we call quantum-coherent nanoscience. We structure this Review according to specific degrees of freedom that can be quantum-coherently controlled in a given nanoscale system, such as charge, spin, mechanical motion and photons. We review the current state of the art and focus on outstanding challenges and opportunities unlocked by the merging of nanoscience and coherent quantum operations.
Electrical control of nuclear spins
Publisher: Springer Science and Business Media LLC
Date: 14-08-2017
Near-Surface Electrical Characterization of Silicon Electronic Devices Using Focused keV-Range Ions
Publisher: American Physical Society (APS)
Date: 14-09-2022
Designing a large scale quantum computer with atomistic simulations
Publisher: IEEE
Date: 06-2014
An ultra-stable 1.5 T permanent magnet assembly for qubit experiments at cryogenic temperatures
Publisher: AIP Publishing
Date: 08-2021
DOI: 10.1063/5.0055318
Abstract: Magnetic fields are a standard tool in the toolbox of every physicist and are required for the characterization of materials, as well as the polarization of spins in nuclear magnetic resonance or electron paramagnetic resonance experiments. Quite often, a static magnetic field of sufficiently large, but fixed, magnitude is suitable for these tasks. Here, we present a permanent magnet assembly that can achieve magnetic field strengths of up to 1.5 T over an air gap length of 7 mm. The assembly is based on a Halbach array of neodymium magnets, with the inclusion of the soft magnetic material Supermendur to boost the magnetic field strength inside the air gap. We present the design, simulation, and characterization of the permanent magnet assembly, measuring an outstanding magnetic field stability with a drift rate of |D| & 2.8 ppb/h. Our measurements demonstrate that this assembly can be used for spin qubit experiments inside a dilution refrigerator, successfully replacing the more expensive and bulky superconducting solenoids.
Breaking the rotating wave approximation for a strongly driven dressed single-electron spin
Publisher: American Physical Society (APS)
Date: 17-10-2016
Integrated silicon qubit platform with single-spin addressability, exchange control and single-shot singlet-triplet readout
Publisher: Springer Science and Business Media LLC
Date: 30-10-2018
DOI: 10.1038/S41467-018-06039-X
Abstract: Silicon quantum dot spin qubits provide a promising platform for large-scale quantum computation because of their compatibility with conventional CMOS manufacturing and the long coherence times accessible using 28 Si enriched material. A scalable error-corrected quantum processor, however, will require control of many qubits in parallel, while performing error detection across the constituent qubits. Spin resonance techniques are a convenient path to parallel two-axis control, while Pauli spin blockade can be used to realize local parity measurements for error detection. Despite this, silicon qubit implementations have so far focused on either single-spin resonance control, or control and measurement via voltage-pulse detuning in the two-spin singlet–triplet basis, but not both simultaneously. Here, we demonstrate an integrated device platform incorporating a silicon metal-oxide-semiconductor double quantum dot that is capable of single-spin addressing and control via electron spin resonance, combined with high-fidelity spin readout in the singlet-triplet basis.
Transport of spin qubits with donor chains under realistic experimental conditions
Publisher: American Physical Society (APS)
Date: 25-07-2016
Storing quantum information for 30 seconds in a nanoelectronic device
Publisher: Springer Science and Business Media LLC
Date: 12-10-2014
Abstract: The spin of an electron or a nucleus in a semiconductor naturally implements the unit of quantum information--the qubit. In addition, because semiconductors are currently used in the electronics industry, developing qubits in semiconductors would be a promising route to realize scalable quantum information devices. The solid-state environment, however, may provide deleterious interactions between the qubit and the nuclear spins of surrounding atoms, or charge and spin fluctuations arising from defects in oxides and interfaces. For materials such as silicon, enrichment of the spin-zero (28)Si isotope drastically reduces spin-bath decoherence. Experiments on bulk spin ensembles in (28)Si crystals have indeed demonstrated extraordinary coherence times. However, it remained unclear whether these would persist at the single-spin level, in gated nanostructures near amorphous interfaces. Here, we present the coherent operation of in idual (31)P electron and nuclear spin qubits in a top-gated nanostructure, fabricated on an isotopically engineered (28)Si substrate. The (31)P nuclear spin sets the new benchmark coherence time (>30 s with Carr-Purcell-Meiboom-Gill (CPMG) sequence) of any single qubit in the solid state and reaches >99.99% control fidelity. The electron spin CPMG coherence time exceeds 0.5 s, and detailed noise spectroscopy indicates that--contrary to widespread belief--it is not limited by the proximity to an interface. Instead, decoherence is probably dominated by thermal and magnetic noise external to the device, and is thus amenable to further improvement.
Coherent electrical control of a single high-spin nucleus in silicon
Publisher: Springer Science and Business Media LLC
Date: 11-03-2020
Silicon quantum processor with robust long-distance qubit couplings
Publisher: Springer Science and Business Media LLC
Date: 06-09-2017
DOI: 10.1038/S41467-017-00378-X
Abstract: Practical quantum computers require a large network of highly coherent qubits, interconnected in a design robust against errors. Donor spins in silicon provide state-of-the-art coherence and quantum gate fidelities, in a platform adapted from industrial semiconductor processing. Here we present a scalable design for a silicon quantum processor that does not require precise donor placement and leaves le space for the routing of interconnects and readout devices. We introduce the flip-flop qubit, a combination of the electron-nuclear spin states of a phosphorus donor that can be controlled by microwave electric fields. Two-qubit gates exploit a second-order electric dipole-dipole interaction, allowing selective coupling beyond the nearest-neighbor, at separations of hundreds of nanometers, while microwave resonators can extend the entanglement to macroscopic distances. We predict gate fidelities within fault-tolerance thresholds using realistic noise models. This design provides a realizable blueprint for scalable spin-based quantum computers in silicon.
Pairwise Decoherence in Coupled Spin Qubit Networks
Publisher: American Physical Society (APS)
Date: 17-11-2006
Logical Qubit in a Linear Array of Semiconductor Quantum Dots
Publisher: American Physical Society (APS)
Date: 06-2018
Donor Spins in Silicon for Quantum Technologies
Publisher: Wiley
Date: 24-07-2020
Abstract: Dopant atoms are ubiquitous in semiconductor technologies, providing the tailored electronic properties that underpin the modern digital information era. Harnessing the quantum nature of these atomic‐scale objects represents a new and exciting technological revolution. In this article, the use of ion‐implanted donor spins in silicon for quantum technologies is described. It is reviewed how to fabricate and operate single‐atom spin qubits in silicon, obtaining some of the most coherent solid‐state qubits, and pathways to scale up these qubits to build large quantum processors are discussed. Heavier group‐V donors with large nuclear spins display electric quadrupole couplings that enable nuclear electric resonance, quantum chaos, and strain sensing. Donor ensembles can be coupled to microwave cavities to develop hybrid quantum Turing machines. Counted, deterministic implantation of single donors, combined with novel methods for precision placement, will allow the integration of in idual donor spins with industry‐standard silicon fabrication processes, making implanted donors a prime physical platform for the second quantum revolution.
Local Magnetic Properties of a Monolayer of Mn12 Single Molecule Magnets
Publisher: American Chemical Society (ACS)
Date: 08-05-2007
DOI: 10.1021/NL070366A
Abstract: The magnetic properties of a monolayer of Mn12 single molecule magnets grafted onto a silicon (Si) substrate have been investigated using depth-controlled beta-detected nuclear magnetic resonance. A low-energy beam of spin-polarized radioactive 8Li was used to probe the local static magnetic field distribution near the Mn12 monolayer in the Si substrate. The resonance line width varies strongly as a function of implantation depth as a result of the magnetic dipolar fields generated by the Mn12 electronic magnetic moments. The temperature dependence of the line width indicates that the magnetic properties of the Mn12 moments in this low-dimensional configuration differ from bulk Mn12.
Observation of the single-electron regime in a highly tunable silicon quantum dot
Publisher: AIP Publishing
Date: 14-12-2009
DOI: 10.1063/1.3272858
Abstract: We report on low-temperature electronic transport measurements of a silicon metal-oxidesemiconductor quantum dot, with independent gate control of electron densities in the leads and the quantum dot island. This architecture allows the dot energy levels to be probed without affecting the electron density in the leads and vice versa. Appropriate gate biasing enables the dot occupancy to be reduced to the single-electron level, as evidenced by magnetospectroscopy measurements of the ground state of the first two charge transitions. Independent gate control of the electron reservoirs also enables discrimination between excited states of the dot and density of states modulations in the leads.
Coherent spin qubit transport in silicon
Publisher: Springer Science and Business Media LLC
Date: 05-07-2021
DOI: 10.1038/S41467-021-24371-7
Abstract: A fault-tolerant quantum processor may be configured using stationary qubits interacting only with their nearest neighbours, but at the cost of significant overheads in physical qubits per logical qubit. Such overheads could be reduced by coherently transporting qubits across the chip, allowing connectivity beyond immediate neighbours. Here we demonstrate high-fidelity coherent transport of an electron spin qubit between quantum dots in isotopically-enriched silicon. We observe qubit precession in the inter-site tunnelling regime and assess the impact of qubit transport using Ramsey interferometry and quantum state tomography techniques. We report a polarization transfer fidelity of 99.97% and an average coherent transfer fidelity of 99.4%. Our results provide key elements for high-fidelity, on-chip quantum information distribution, as long envisaged, reinforcing the scaling prospects of silicon-based spin qubits.
Exploring quantum chaos with a single nuclear spin
Publisher: American Physical Society (APS)
Date: 05-10-2018
Single spins in silicon carbide
Publisher: Springer Science and Business Media LLC
Date: 12-2014
DOI: 10.1038/NMAT4171
Quantum tunnelling of magnetization in Mn 12 - ac studied by 55 Mn NMR
Publisher: Elsevier BV
Date: 07-2003
An addressable quantum dot qubit with fault-tolerant control-fidelity
Publisher: Springer Science and Business Media LLC
Date: 12-10-2014
Abstract: Exciting progress towards spin-based quantum computing has recently been made with qubits realized using nitrogen-vacancy centres in diamond and phosphorus atoms in silicon. For ex le, long coherence times were made possible by the presence of spin-free isotopes of carbon and silicon. However, despite promising single-atom nanotechnologies, there remain substantial challenges in coupling such qubits and addressing them in idually. Conversely, lithographically defined quantum dots have an exchange coupling that can be precisely engineered, but strong coupling to noise has severely limited their dephasing times and control fidelities. Here, we combine the best aspects of both spin qubit schemes and demonstrate a gate-addressable quantum dot qubit in isotopically engineered silicon with a control fidelity of 99.6%, obtained via Clifford-based randomized benchmarking and consistent with that required for fault-tolerant quantum computing. This qubit has dephasing time T2* = 120 μs and coherence time T2 = 28 ms, both orders of magnitude larger than in other types of semiconductor qubit. By gate-voltage-tuning the electron g*-factor we can Stark shift the electron spin resonance frequency by more than 3,000 times the 2.4 kHz electron spin resonance linewidth, providing a direct route to large-scale arrays of addressable high-fidelity qubits that are compatible with existing manufacturing technologies.
Circuit-quantum electrodynamics with direct magnetic coupling to single-atom spin qubits in isotopically enriched 28Si
Publisher: AIP Publishing
Date: 08-2014
DOI: 10.1063/1.4893242
Abstract: Recent advances in silicon nanofabrication have allowed the manipulation of spin qubits that are extremely isolated from noise sources, being therefore the semiconductor equivalent of single atoms in vacuum. We investigate the possibility of directly coupling an electron spin qubit to a superconducting resonator magnetic vacuum field. By using resonators modified to increase the vacuum magnetic field at the qubit location, and isotopically purified 28Si substrates, it is possible to achieve coupling rates faster than the single spin dephasing. This opens up new avenues for circuit-quantum electrodynamics with spins, and provides a pathway for dispersive read-out of spin qubits via superconducting resonators.
Strain-Induced Spin-Resonance Shifts in Silicon Devices
Publisher: American Physical Society (APS)
Date: 10-04-2018
A dressed spin qubit in silicon
Publisher: Springer Science and Business Media LLC
Date: 17-10-2017
Abstract: Coherent dressing of a quantum two-level system provides access to a new quantum system with improved properties-a different and easily tunable level splitting, faster control and longer coherence times. In our work we investigate the properties of the dressed, donor-bound electron spin in silicon, and assess its potential as a quantum bit in scalable architectures. The two dressed spin-polariton levels constitute a quantum bit that can be coherently driven with an oscillating magnetic field, an oscillating electric field, frequency modulation of the driving field or a simple detuning pulse. We measure coherence times of and , one order of magnitude longer than those of the undressed spin. Furthermore, the use of the dressed states enables coherent coupling of the solid-state spins to electric fields and mechanical oscillations.
Controllable freezing of the nuclear spin bath in a single-atom spin qubit
Publisher: American Association for the Advancement of Science (AAAS)
Date: 03-07-2020
Abstract: The presence or absence of an electron controls the freezing of the nuclear spin bath coupled to a single-atom qubit in silicon.
Assessment of a Silicon Quantum Dot Spin Qubit Environment via Noise Spectroscopy
Publisher: American Physical Society (APS)
Date: 05-10-2018
Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting
Publisher: Springer Science and Business Media LLC
Date: 27-06-2013
DOI: 10.1038/NCOMMS3069
Abstract: Although silicon is a promising material for quantum computation, the degeneracy of the conduction band minima (valleys) must be lifted with a splitting sufficient to ensure the formation of well-defined and long-lived spin qubits. Here we demonstrate that valley separation can be accurately tuned via electrostatic gate control in a metal-oxide-semiconductor quantum dot, providing splittings spanning 0.3-0.8 meV. The splitting varies linearly with applied electric field, with a ratio in agreement with atomistic tight-binding predictions. We demonstrate single-shot spin read-out and measure the spin relaxation for different valley configurations and dot occupancies, finding one-electron lifetimes exceeding 2 s. Spin relaxation occurs via phonon emission due to spin-orbit coupling between the valley states, a process not previously anticipated for silicon quantum dots. An analytical theory describes the magnetic field dependence of the relaxation rate, including the presence of a dramatic rate enhancement (or hot-spot) when Zeeman and valley splittings coincide.
Pauli Blockade in Silicon Quantum Dots with Spin-Orbit Control
Publisher: American Physical Society (APS)
Date: 07-01-2021
Coherent control via weak measurements in P-31 single-atom electron and nuclear spin qubits
Publisher: American Physical Society (APS)
Date: 05-10-2018
Spin-orbit coupling and operation of multivalley spin qubits
Publisher: American Physical Society (APS)
Date: 05-11-2015
Pneumatic Vehicular Suspension With a Controllable Stiffness Spring
Publisher: ASMEDC
Date: 2006
Abstract: This paper deals with the design of a new vehicular pneumatic suspension. It presents an innovative scheme of suspension, using a special 3-membrane deformable fluid spring. The spring is provided with three internal chambers, supplied by a compressible fluid. Each chamber presents a different volume gradient versus the stroke a proper variation of the connection between the chambers, that may be performed in few milliseconds, determines a stiffness variation of the air spring. The spring structure and the related mathematical models are presented. Afterwards the process of adaptation of the component to a specific mid-low class car model, in order to achieve a prototypal phase, is described. Finally the results of some dynamic simulations of the car behavior are shown.
An electrically driven single-atom “flip-flop” qubit
Publisher: American Association for the Advancement of Science (AAAS)
Date: 10-02-2023
Abstract: The spins of atoms and atom-like systems are among the most coherent objects in which to store quantum information. However, the need to address them using oscillating magnetic fields hinders their integration with quantum electronic devices. Here, we circumvent this hurdle by operating a single-atom “flip-flop” qubit in silicon, where quantum information is encoded in the electron-nuclear states of a phosphorus donor. The qubit is controlled using local electric fields at microwave frequencies, produced within a metal-oxide-semiconductor device. The electrical drive is mediated by the modulation of the electron-nuclear hyperfine coupling, a method that can be extended to many other atomic and molecular systems and to the hyperpolarization of nuclear spin ensembles. These results pave the way to the construction of solid-state quantum processors where dense arrays of atoms can be controlled using only local electric fields.
Independent Control of Dot Occupancy and Reservoir Electron Density in a One-electron Quantum Dot
Publisher: AIP
Date: 2011
DOI: 10.1063/1.3666397
Interface-induced spin-orbit interaction in silicon quantum dots and prospects for scalability
Publisher: American Physical Society (APS)
Date: 04-06-2018
Single atom devices by ion implantation
Publisher: IOP Publishing
Date: 18-03-2015
DOI: 10.1088/0953-8984/27/15/154204
Abstract: To expand the capabilities of semiconductor devices for new functions exploiting the quantum states of single donors or other impurity atoms requires a deterministic fabrication method. Ion implantation is a standard tool of the semiconductor industry and we have developed pathways to deterministic ion implantation to address this challenge. Although ion straggling limits the precision with which atoms can be positioned, for single atom devices it is possible to use post-implantation techniques to locate favourably placed atoms in devices for control and readout. However, large-scale devices will require improved precision. We examine here how the method of ion beam induced charge, already demonstrated for the deterministic ion implantation of 14 keV P donor atoms in silicon, can be used to implant a non-Poisson distribution of ions in silicon. Further, we demonstrate the method can be developed to higher precision by the incorporation of new deterministic ion implantation strategies that employ on-chip detectors with internal charge gain. In a silicon device we show a pulse height spectrum for 14 keV P ion impact that shows an internal gain of 3 that has the potential of allowing deterministic implantation of sub-14 keV P ions with reduced straggling.
Quantifying the quantum gate fidelity of single-atom spin qubits in silicon by randomized benchmarking
Publisher: IOP Publishing
Date: 18-03-2015
DOI: 10.1088/0953-8984/27/15/154205
Abstract: Building upon the demonstration of coherent control and single-shot readout of the electron and nuclear spins of in idual (31)P atoms in silicon, we present here a systematic experimental estimate of quantum gate fidelities using randomized benchmarking of 1-qubit gates in the Clifford group. We apply this analysis to the electron and the ionized (31)P nucleus of a single P donor in isotopically purified (28)Si. We find average gate fidelities of 99.95% for the electron and 99.99% for the nuclear spin. These values are above certain error correction thresholds and demonstrate the potential of donor-based quantum computing in silicon. By studying the influence of the shape and power of the control pulses, we find evidence that the present limitation to the gate fidelity is mostly related to the external hardware and not the intrinsic behaviour of the qubit.
Bell's inequality violation with spins in silicon
Publisher: Springer Science and Business Media LLC
Date: 16-11-2016
Abstract: Bell's theorem proves the existence of entangled quantum states with no classical counterpart. An experimental violation of Bell's inequality demands simultaneously high fidelities in the preparation, manipulation and measurement of multipartite quantum entangled states, and provides a single-number benchmark for the performance of devices that use such states for quantum computing. We demonstrate a Bell/ Clauser-Horne-Shimony-Holt inequality violation with Bell signals up to 2.70(9), using the electron and the nuclear spins of a single phosphorus atom embedded in a silicon nanoelectronic device. Two-qubit state tomography reveals that our prepared states match the target maximally entangled Bell states with >96% fidelity. These experiments demonstrate complete control of the two-qubit Hilbert space of a phosphorus atom and highlight the important function of the nuclear qubit to expand the computational basis and maximize the readout fidelity.
What would you do with 1000 qubits?
Publisher: IOP Publishing
Date: 19-06-2018
Electron spin relaxation of single phosphorus donors in metal-oxide-semiconductor nanoscale devices
Publisher: American Physical Society (APS)
Date: 14-05-2019
A two-qubit logic gate in silicon
Publisher: Springer Science and Business Media LLC
Date: 10-2015
DOI: 10.1038/NATURE15263
Abstract: Quantum computation requires qubits that can be coupled in a scalable manner, together with universal and high-fidelity one- and two-qubit logic gates. Many physical realizations of qubits exist, including single photons, trapped ions, superconducting circuits, single defects or atoms in diamond and silicon, and semiconductor quantum dots, with single-qubit fidelities that exceed the stringent thresholds required for fault-tolerant quantum computing. Despite this, high-fidelity two-qubit gates in the solid state that can be manufactured using standard lithographic techniques have so far been limited to superconducting qubits, owing to the difficulties of coupling qubits and dephasing in semiconductor systems. Here we present a two-qubit logic gate, which uses single spins in isotopically enriched silicon and is realized by performing single- and two-qubit operations in a quantum dot system using the exchange interaction, as envisaged in the Loss-DiVincenzo proposal. We realize CNOT gates via controlled-phase operations combined with single-qubit operations. Direct gate-voltage control provides single-qubit addressability, together with a switchable exchange interaction that is used in the two-qubit controlled-phase gate. By independently reading out both qubits, we measure clear anticorrelations in the two-spin probabilities of the CNOT gate.
Full configuration interaction simulations of exchange-coupled donors in silicon using multi-valley effective mass theory
Publisher: IOP Publishing
Date: 07-2021
Abstract: Donor spins in silicon have achieved record values of coherence times and single-qubit gate fidelities. The next stage of development involves demonstrating high-fidelity two-qubit logic gates, where the most natural coupling is the exchange interaction. To aid the efficient design of scalable donor-based quantum processors, we model the two-electron wave function using a full configuration interaction method within a multi-valley effective mass theory. We exploit the high computational efficiency of our code to investigate the exchange interaction, valley population, and electron densities for two phosphorus donors in a wide range of lattice positions, orientations, and as a function of applied electric fields. The outcomes are visualized with interactive images where donor positions can be swept while watching the valley and orbital components evolve accordingly. Our results provide a physically intuitive and quantitatively accurate understanding of the placement and tuning criteria necessary to achieve high-fidelity two-qubit gates with donors in silicon.
Silicon quantum electronics
Publisher: American Physical Society (APS)
Date: 10-07-2013
Fast Coherent Control of a Nitrogen-Vacancy-Center Spin Ensemble Using a Dielectric Resonator at Cryogenic Temperatures
Publisher: American Physical Society (APS)
Date: 26-10-2021
Silicon quantum dots: fine-tuning to maturity
Publisher: IOP Publishing
Date: 20-11-2015
DOI: 10.1088/0957-4484/26/50/502501
Abstract: Quantum dots in semiconductor heterostructures provide one of the most flexible platforms for the study of quantum phenomena at the nanoscale. The surging interest in using quantum dots for quantum computation is forcing researchers to rethink fabrication and operation methods, to obtain highly tunable dots in spin-free host materials, such as silicon. Borselli and colleagues report in Nanotechnology the fabrication of a novel Si/SiGe double quantum dot device, which combines an ultra-low disorder Si/SiGe accumulation-mode heterostructure with a stack of overlapping control gates, ensuring tight confining potentials and exquisite tunability. This work signals the technological maturity of silicon quantum dots, and their readiness to be applied to challenging projects in quantum information science.
Dynamics and thermalization of the nuclear spin bath in the single-molecule magnet
Publisher:
American Physical Society (APS)
Date:
20-11-2007
Publisher: American Physical Society (APS)
Date: 20-11-2007
Single-Shot Readout and Relaxation of Singlet and Triplet States in Exchange-Coupled
Publisher:
American Physical Society (APS)
Date:
09-06-2014
Publisher: American Physical Society (APS)
Date: 09-06-2014
Observation of Zero-Point Quantum Fluctuations of a Single-Molecule Magnet through the Relaxation of its Nuclear Spin Bath
Publisher: American Physical Society (APS)
Date: 18-03-2014
High-fidelity adiabatic inversion of a P-31 electron spin qubit in natural silicon
Publisher: AIP Publishing
Date: 03-03-2014
DOI: 10.1063/1.4867905
Deterministic Shallow Dopant Implantation in Silicon with Detection Confidence Upper‐Bound to 99.85% by Ion–Solid Interactions
Publisher: Wiley
Date: 12-11-2022
Abstract: Silicon chips containing arrays of single dopant atoms can be the material of choice for classical and quantum devices that exploit single donor spins. For ex le, group‐V donors implanted in isotopically purified 28 Si crystals are attractive for large‐scale quantum computers. Useful attributes include long nuclear and electron spin lifetimes of 31 P, hyperfine clock transitions in 209 Bi or electrically controllable 123 Sb nuclear spins. Promising architectures require the ability to fabricate arrays of in idual near‐surface dopant atoms with high yield. Here, an on‐chip detector electrode system with 70 eV root‐mean‐square noise (≈20 electrons) is employed to demonstrate near‐room‐temperature implantation of single 14 keV 31 P + ions. The physics model for the ion–solid interaction shows an unprecedented upper‐bound single‐ion‐detection confidence of 99.85 ± 0.02% for near‐surface implants. As a result, the practical controlled silicon doping yield is limited by materials engineering factors including surface gate oxides in which detected ions may stop. For a device with 6 nm gate oxide and 14 keV 31 P + implants, a yield limit of 98.1% is demonstrated. Thinner gate oxides allow this limit to converge to the upper‐bound. Deterministic single‐ion implantation can therefore be a viable materials engineering strategy for scalable dopant architectures in silicon devices.
Orbital and valley state spectra of a few-electron silicon quantum dot
Publisher: American Physical Society (APS)
Date: 12-09-2012
POSSIBLE EVIDENCE OF CHARGE-STRIPE ORDERING IN THE ab-PLANE RESISTIVITY OF STRONGLY UNDERDOPED La2-xSrxCuO4 SINGLE CRYSTA
Publisher: World Scientific Pub Co Pte Lt
Date: 30-10-2000
DOI: 10.1142/S0217979200002892
Abstract: We measured the ab-plane resistivity of La 2-x Sr x CuO 4 underdoped single crystals (x = 0.052 and x=0.06) between 4.2 and 300 K by using an AC version of the Van der Pauw technique. We suggest that a possible scenario of charge-stripe ordering at the lowering of the temperature can be delineated by starting from the main features of the ρ ab (T) curves of these s les. In particular, the deviation from the linearity of the ab-plane resistivity, occurring at a temperature T ch , could be related to the beginning of the charge localization, and the upturn of ρ ab to the progressive pinning of the resulting charge stripes. By starting from an analysis of our ab-plane resistivity curves, we determined the temperature of charge ordering T ch for our s les, thus extending in consistent way the T ch vs. x curve reported in literature to the very low-doping region of the phase diagram.
Precision tomography of a three-qubit donor quantum processor in silicon.
Publisher: Springer Science and Business Media LLC
Date: 19-01-2022
DOI: 10.1038/S41586-021-04292-7
Abstract: Nuclear spins were among the first physical platforms to be considered for quantum information processing
Development of an Undergraduate Quantum Engineering Degree
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Robust two-qubit gates for donors in silicon controlled by hyperfine interactions
Publisher: American Physical Society (APS)
Date: 06-06-2014
Silicon qubit fidelities approaching incoherent noise limits via pulse engineering
Publisher: Springer Science and Business Media LLC
Date: 15-04-2019
A single-atom electron spin qubit in silicon
Publisher: Springer Science and Business Media LLC
Date: 09-2012
DOI: 10.1038/NATURE11449
Abstract: A single atom is the prototypical quantum system, and a natural candidate for a quantum bit, or qubit--the elementary unit of a quantum computer. Atoms have been successfully used to store and process quantum information in electromagnetic traps, as well as in diamond through the use of the nitrogen-vacancy-centre point defect. Solid-state electrical devices possess great potential to scale up such demonstrations from few-qubit control to larger-scale quantum processors. Coherent control of spin qubits has been achieved in lithographically defined double quantum dots in both GaAs (refs 3-5) and Si (ref. 6). However, it is a formidable challenge to combine the electrical measurement capabilities of engineered nanostructures with the benefits inherent in atomic spin qubits. Here we demonstrate the coherent manipulation of an in idual electron spin qubit bound to a phosphorus donor atom in natural silicon, measured electrically via single-shot read-out. We use electron spin resonance to drive Rabi oscillations, and a Hahn echo pulse sequence reveals a spin coherence time exceeding 200 µs. This time should be even longer in isotopically enriched (28)Si s les. Combined with a device architecture that is compatible with modern integrated circuit technology, the electron spin of a single phosphorus atom in silicon should be an excellent platform on which to build a scalable quantum computer.
Operation of a silicon quantum processor unit cell above one kelvin
Publisher: Springer Science and Business Media LLC
Date: 15-04-2020
Conditional quantum operation of two exchange-coupled single-donor spin qubits in a MOS-compatible silicon device
Publisher: Springer Science and Business Media LLC
Date: 08-01-2021
DOI: 10.1038/S41467-020-20424-5
Abstract: Silicon nanoelectronic devices can host single-qubit quantum logic operations with fidelity better than 99.9%. For the spins of an electron bound to a single-donor atom, introduced in the silicon by ion implantation, the quantum information can be stored for nearly 1 second. However, manufacturing a scalable quantum processor with this method is considered challenging, because of the exponential sensitivity of the exchange interaction that mediates the coupling between the qubits. Here we demonstrate the conditional, coherent control of an electron spin qubit in an exchange-coupled pair of 31 P donors implanted in silicon. The coupling strength, J = 32.06 ± 0.06 MHz, is measured spectroscopically with high precision. Since the coupling is weaker than the electron-nuclear hyperfine coupling A ≈ 90 MHz which detunes the two electrons, a native two-qubit controlled-rotation gate can be obtained via a simple electron spin resonance pulse. This scheme is insensitive to the precise value of J , which makes it suitable for the scale-up of donor-based quantum computers in silicon that exploit the metal-oxide-semiconductor fabrication protocols commonly used in the classical electronics industry.
Electrically controlling single-spin qubits in a continuous microwave field
Publisher: American Association for the Advancement of Science (AAAS)
Date: 03-04-2015
Abstract: Control of in idual spin qubits through local electric fields, suitable for large-scale silicon quantum computers.
Quantum Nanomagnets and Nuclear Spins: An Overview
Publisher: Springer Netherlands
Date: 2008
Controlling Spin-Orbit Interactions in Silicon Quantum Dots Using Magnetic Field Direction
Publisher: American Physical Society (APS)
Date: 10-05-2019
Approach of single-molecule magnets to thermal equilibrium
Publisher: Elsevier BV
Date: 04-2004
Impact of g -factors and valleys on spin qubits in a silicon double quantum dot
Publisher: American Physical Society (APS)
Date: 05-07-2017
Nuclear Spin Dynamics in the Quantum Regime of a Single-Molecule Magnet
Publisher: American Physical Society (APS)
Date: 04-11-2004
Resonant tunnelling features in quantum dots
Publisher: IOP Publishing
Date: 22-06-2010
DOI: 10.1088/0957-4484/21/27/274018
Abstract: We present a systematic review of features due to resonant electron tunnelling, observable in transport spectroscopy experiments on quantum dots and single donors. The review covers features attributable to intrinsic properties of the dot (orbital, spin and valley states) as well as extrinsic effects (phonon hoton emission/absorption, features in the charge reservoirs, coupling to nearby charge centres). We focus on the most common operating conditions, neglecting effects due to strong coupling to the leads. By discussing the experimental signatures of each type of feature, we aim at providing practical methods to distinguish between their different physical origins. The correct classification of the resonant tunnelling features is an essential requirement to understand the details of the confining potential or to predict the performance of the dot for quantum information processing.
Coherent spin control of s-, p-, d- and f-electrons in a silicon quantum dot
Publisher: Springer Science and Business Media LLC
Date: 11-02-2020
DOI: 10.1038/S41467-019-14053-W
Abstract: Once the periodic properties of elements were unveiled, chemical behaviour could be understood in terms of the valence of atoms. Ideally, this rationale would extend to quantum dots, and quantum computation could be performed by merely controlling the outer-shell electrons of dot-based qubits. Imperfections in semiconductor materials disrupt this analogy, so real devices seldom display a systematic many-electron arrangement. We demonstrate here an electrostatically confined quantum dot that reveals a well defined shell structure. We observe four shells (31 electrons) with multiplicities given by spin and valley degrees of freedom. Various fillings containing a single valence electron—namely 1, 5, 13 and 25 electrons—are found to be potential qubits. An integrated micromagnet allows us to perform electrically-driven spin resonance (EDSR), leading to faster Rabi rotations and higher fidelity single qubit gates at higher shell states. We investigate the impact of orbital excitations on single qubits as a function of the dot deformation and exploit it for faster qubit control.
Vibration-induced electrical noise in a cryogen-free dilution refrigerator: Characterization, mitigation, and impact on qubit coherence
Publisher: AIP Publishing
Date: 07-2016
DOI: 10.1063/1.4959153
Abstract: Cryogen-free low-temperature setups are becoming more prominent in experimental science due to their convenience and reliability, and concern about the increasing scarcity of helium as a natural resource. Despite not having any moving parts at the cold end, pulse tube cryocoolers introduce vibrations that can be detrimental to the experiments. We characterize the coupling of these vibrations to the electrical signal observed on cables installed in a cryogen-free dilution refrigerator. The dominant electrical noise is in the 5–10 kHz range and its magnitude is found to be strongly temperature dependent. We test the performance of different cables designed to diagnose and tackle the noise, and find triboelectrics to be the dominant mechanism coupling the vibrations to the electrical signal. Flattening a semi-rigid cable or jacketing a flexible cable in order to restrict movement within the cable, successfully reduces the noise level by over an order of magnitude. Furthermore, we characterize the effect of the pulse tube vibrations on an electron spin qubit device in this setup. Coherence measurements are used to map out the spectrum of the noise experienced by the qubit, revealing spectral components matching the spectral signature of the pulse tube.
Irreversibility line of overdopedBi
Publisher:
American Physical Society (APS)
Date:
04-2000
Publisher: American Physical Society (APS)
Date: 04-2000
High-fidelity readout and control of a nuclear spin qubit in silicon
Publisher: Springer Science and Business Media LLC
Date: 04-2013
DOI: 10.1038/NATURE12011
Abstract: Detection of nuclear spin precession is critical for a wide range of scientific techniques that have applications in erse fields including analytical chemistry, materials science, medicine and biology. Fundamentally, it is possible because of the extreme isolation of nuclear spins from their environment. This isolation also makes single nuclear spins desirable for quantum-information processing, as shown by pioneering studies on nitrogen-vacancy centres in diamond. The nuclear spin of a (31)P donor in silicon is very promising as a quantum bit: bulk measurements indicate that it has excellent coherence times and silicon is the dominant material in the microelectronics industry. Here we demonstrate electrical detection and coherent manipulation of a single (31)P nuclear spin qubit with sufficiently high fidelities for fault-tolerant quantum computing. By integrating single-shot readout of the electron spin with on-chip electron spin resonance, we demonstrate quantum non-demolition and electrical single-shot readout of the nuclear spin with a readout fidelity higher than 99.8 percent-the highest so far reported for any solid-state qubit. The single nuclear spin is then operated as a qubit by applying coherent radio-frequency pulses. For an ionized (31)P donor, we find a nuclear spin coherence time of 60 milliseconds and a one-qubit gate control fidelity exceeding 98 percent. These results demonstrate that the dominant technology of modern electronics can be adapted to host a complete electrical measurement and control platform for nuclear-spin-based quantum-information processing.
VORTEX GLASS TRANSITION VERSUS IRREVERSIBILITY LINE IN SUPERCONDUCTING BKBO
Publisher: World Scientific Pub Co Pte Lt
Date: 30-08-2002
DOI: 10.1142/S0217979202014012
Abstract: Simultaneous magnetotransport and torque magnetization measurements have been performed on superconducting (B, Ka)BiO 3 single crystals. The measurements have been carried out at very low temperatures (0.03 k T 2 K) and up to high magnetic fields: (30Tesla ~ H c2 (0)). The resistivity drops below the experimental resolution for a magnetic field H R (T) which is very close to the irreversibility line deduced from torque magnetometry. Close to H R (H) the resistive transition can be well by the vortex-glass scaling formalism 1 suggesting that the vortex solid melts into a liquid for H H R . Our measurements show that the irreversibility line in (K, Ba)BiO 3 is closely related to this vortex glass transition line but, surprisingly, a large reversible (i.e. liquid) phase can still be observed at very low temperatures (30 m K ).
Probe and control of the reservoir density of states in single-electron devices
Publisher: American Physical Society (APS)
Date: 08-04-2010
Spin readout and addressability of phosphorus-donor clusters in silicon
Publisher: Springer Science and Business Media LLC
Date: 18-06-2013
DOI: 10.1038/NCOMMS3017
Abstract: The spin states of an electron bound to a single phosphorus donor in silicon show remarkably long coherence and relaxation times, which makes them promising building blocks for the realization of a solid-state quantum computer. Here we demonstrate, by high-fidelity (93%) electrical spin readout, that a long relaxation time T1 of about 2 s, at B=1.2 T and T≈100 mK, is also characteristic of electronic spin states associated with a cluster of few phosphorus donors, suggesting their suitability as hosts for spin qubits. Owing to the difference in the hyperfine coupling, electronic spin transitions of such clusters can be sufficiently distinct from those of a single phosphorus donor. Our atomistic tight-binding calculations reveal that when neighbouring qubits are hosted by a single phosphorus atom and a cluster of two phosphorus donors, the difference in their electron spin resonance frequencies allows qubit rotations with error rates ≈10(-4). These results provide a new approach to achieving in idual qubit addressability.
Architecture for high-sensitivity single-shot readout and control of the electron spin of individual donors in silicon
Publisher: American Physical Society (APS)
Date: 14-08-2009
Transport Spectroscopy of Single Phosphorus Donors in a Silicon Nanoscale Transistor
Publisher: American Chemical Society (ACS)
Date: 12-2009
DOI: 10.1021/NL901635J
Abstract: We have developed nanoscale double-gated field-effect-transistors for the study of electron states and transport properties of single deliberately implanted phosphorus donors. The devices provide a high-level of control of key parameters required for potential applications in nanoelectronics. For the donors, we resolve transitions corresponding to two charge states successively occupied by spin down and spin up electrons. The charging energies and the Lande g-factors are consistent with expectations for donors in gated nanostructures.
Quantum search on a single-atom qudit
Publisher: Springer Science and Business Media LLC
Date: 2018
Single-atom spin qubits in silicon
Publisher: IEEE
Date: 12-2014
Exchange Coupling in a Linear Chain of Three Quantum-Dot Spin Qubits in Silicon
Publisher: American Chemical Society (ACS)
Date: 22-01-2021
Noninvasive Spatial Metrology of Single-Atom Devices
Publisher: American Chemical Society (ACS)
Date: 18-04-2013
DOI: 10.1021/NL303863S
Abstract: The exact location of a single dopant atom in a nanostructure can influence or fully determine the functionality of highly scaled transistors or spin-based devices. We demonstrate here a noninvasive spatial metrology technique, based on the microscopic modeling of three electrical measurements on a single-atom (phosphorus in silicon) spin qubit device: hyperfine coupling, ground state energy, and capacitive coupling to nearby gates. This technique allows us to locate the qubit atom with a precision of ±2.5 nm in two directions and ±15 nm in the third direction, which represents a 1500-fold improvement with respect to the prefabrication statistics obtainable from the ion implantation parameters.
Deterministic Atom Placement by Ion Implantation: Few and Single Atom Devices for Quantum Computer Technology
Publisher: IEEE
Date: 09-2017
A silicon quantum-dot-coupled nuclear spin qubit
Publisher: Springer Science and Business Media LLC
Date: 09-12-2020
DOI: 10.1038/S41565-019-0587-7
Abstract: Single nuclear spins in the solid state are a potential future platform for quantum computing
3D-melting features of the irreversibility line in overdoped Bi2Sr2CuO6 at ultra-low temperature and high magnetic field
Publisher: Elsevier BV
Date: 11-2000
Measuring out-of-time-ordered correlation functions without reversing time evolution
Publisher: American Physical Society (APS)
Date: 19-10-2022
ab-plane resistivity and possible charge stripe ordering in strongly underdoped La2−xSrxCuO4 single crystals
Publisher: Elsevier BV
Date: 11-2000
Scalable quantum computing with ion-implanted dopant atoms in Silicon
Publisher: IEEE
Date: 12-2019
Nanoscale broadband transmission lines for spin qubit control
Publisher: IOP Publishing
Date: 07-12-2012
DOI: 10.1088/0957-4484/24/1/015202
Abstract: The intense interest in spin-based quantum information processing has caused an increasing overlap between the two traditionally distinct disciplines of magnetic resonance and nanotechnology. In this work we discuss rigorous design guidelines to integrate microwave circuits with charge-sensitive nanostructures, and describe how to simulate such structures accurately and efficiently. We present a new design for an on-chip, broadband, nanoscale microwave line that optimizes the magnetic field used to drive a spin-based quantum bit (or qubit) while minimizing the disturbance to a nearby charge sensor. This new structure was successfully employed in a single-spin qubit experiment, and shows that the simulations accurately predict the magnetic field values even at frequencies as high as 30 GHz.
In situ amplification of spin echoes within a kinetic inductance parametric amplifier
Publisher: American Association for the Advancement of Science (AAAS)
Date: 10-03-2023
Abstract: The use of superconducting microresonators together with quantum-limited Josephson parametric lifiers has enhanced the sensitivity of pulsed electron spin resonance (ESR) measurements by more than four orders of magnitude. So far, the microwave resonators and lifiers have been designed as separate components due to the incompatibility of Josephson junction–based devices with magnetic fields. This has produced complex spectrometers and raised technical barriers toward adoption of the technique. Here, we circumvent this issue by coupling an ensemble of spins directly to a weakly nonlinear and magnetic field–resilient superconducting microwave resonator. We perform pulsed ESR measurements with a 1-pL mode volume containing 6 × 10 7 spins and lify the resulting signals within the device. When considering only those spins that contribute to the detected signals, we find a sensitivity of 2.8 × 1 0 3 spins / Hz for a Hahn echo sequence at a temperature of 400 mK. In situ lification is demonstrated at fields up to 254 mT, highlighting the technique’s potential for application under conventional ESR operating conditions.
Electron tunnel rates in a donor-silicon single electron transistor hybrid
Publisher: American Physical Society (APS)
Date: 15-06-2010
Pauli spin blockade in a highly tunable silicon double quantum dot
Publisher: Springer Science and Business Media LLC
Date: 07-10-2011
DOI: 10.1038/SREP00110
Resistivity and electron-phonon coupling in YNi2B2C single crystals
Publisher: Elsevier BV
Date: 11-2000
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