ORCID Profile
0000-0002-5473-6481
Current Organisation
Australian National University
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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.
Quantum Physics | Quantum Information, Computation and Communication | Nanometrology | Condensed Matter Physics | Surfaces and Structural Properties of Condensed Matter | Quantum Optics | Electronic and Magnetic Properties of Condensed Matter; Superconductivity | Biological Physics | Nanofabrication, Growth and Self Assembly
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in Technology | Integrated Circuits and Devices | Expanding Knowledge in the Biological Sciences |
Publisher: American Physical Society (APS)
Date: 25-04-2013
Publisher: American Chemical Society (ACS)
Date: 04-05-2023
Publisher: American Chemical Society (ACS)
Date: 19-03-2021
Publisher: American Physical Society (APS)
Date: 31-01-2014
Publisher: American Chemical Society (ACS)
Date: 11-09-2017
DOI: 10.1021/ACS.NANOLETT.7B01796
Abstract: In recent years, solid-state spin systems have emerged as promising candidates for quantum information processing. Prominent ex les are the nitrogen-vacancy (NV) center in diamond, phosphorus dopants in silicon (Si:P), rare-earth ions in solids, and V
Publisher: Springer Science and Business Media LLC
Date: 25-09-2017
DOI: 10.1038/S41598-017-10461-4
Abstract: Emergence of polyphagous herbivorous insects entails significant adaptation to recognize, detoxify and digest a variety of host-plants. Despite of its biological and practical importance - since insects eat 20% of crops - no exhaustive analysis of gene repertoires required for adaptations in generalist insect herbivores has previously been performed. The noctuid moth Spodoptera frugiperda ranks as one of the world’s worst agricultural pests. This insect is polyphagous while the majority of other lepidopteran herbivores are specialist. It consists of two morphologically indistinguishable strains (“C” and “R”) that have different host plant ranges. To describe the evolutionary mechanisms that both enable the emergence of polyphagous herbivory and lead to the shift in the host preference, we analyzed whole genome sequences from laboratory and natural populations of both strains. We observed huge expansions of genes associated with chemosensation and detoxification compared with specialist Lepidoptera. These expansions are largely due to tandem duplication, a possible adaptation mechanism enabling polyphagy. In iduals from natural C and R populations show significant genomic differentiation. We found signatures of positive selection in genes involved in chemoreception, detoxification and digestion, and copy number variation in the two latter gene families, suggesting an adaptive role for structural variation.
Publisher: IOP Publishing
Date: 30-06-2014
Publisher: American Physical Society (APS)
Date: 06-12-2021
Publisher: IOP Publishing
Date: 26-11-2018
Publisher: American Physical Society (APS)
Date: 28-04-0001
Publisher: American Physical Society (APS)
Date: 18-11-2016
Publisher: American Physical Society (APS)
Date: 08-04-2015
Publisher: Elsevier BV
Date: 03-2021
Publisher: The Optical Society
Date: 14-09-2018
Publisher: American Physical Society (APS)
Date: 31-08-2016
Publisher: OSA
Date: 2017
Publisher: IOP Publishing
Date: 27-01-2015
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR02093G
Abstract: The nitrogen-vacancy (NV) centre in diamond is a remarkable optical defect with broad applications. We demonstrate that its fluorescence emission is enhanced at high magnetic fields with low excitation power.
Publisher: Springer Science and Business Media LLC
Date: 15-01-2019
DOI: 10.1038/S41467-018-08185-8
Abstract: Optically addressable spins associated with defects in wide-bandgap semiconductors are versatile platforms for quantum information processing and nanoscale sensing, where spin-dependent inter-system crossing transitions facilitate optical spin initialization and readout. Recently, the van der Waals material hexagonal boron nitride (h-BN) has emerged as a robust host for quantum emitters, promising efficient photon extraction and atom-scale engineering, but observations of spin-related effects have remained thus far elusive. Here, we report room-temperature observations of strongly anisotropic photoluminescence patterns as a function of applied magnetic field for select quantum emitters in h-BN. Field-dependent variations in the steady-state photoluminescence and photon emission statistics are consistent with an electronic model featuring a spin-dependent inter-system crossing between triplet and singlet manifolds, indicating that optically-addressable spin defects are present in h-BN.
Publisher: IOP Publishing
Date: 21-02-2011
Publisher: SPIE
Date: 11-02-2010
DOI: 10.1117/12.843777
Publisher: American Physical Society (APS)
Date: 28-07-2019
Publisher: Springer Science and Business Media LLC
Date: 22-10-2021
Publisher: AIP Publishing
Date: 10-03-2014
DOI: 10.1063/1.4868128
Abstract: Synthetic diamond production is a key to the development of quantum metrology and quantum information applications of diamond. The major quantum sensor and qubit candidate in diamond is the nitrogen-vacancy (NV) color center. This lattice defect comes in four different crystallographic orientations leading to an intrinsic inhomogeneity among NV centers, which is undesirable in some applications. Here, we report a microwave plasma-assisted chemical vapor deposition diamond growth technique on (111)-oriented substrates, which yields perfect alignment (94% ± 2%) of as-grown NV centers along a single crystallographic direction. In addition, clear evidence is found that the majority (74% ± 4%) of the aligned NV centers were formed by the nitrogen being first included in the (111) growth surface and then followed by the formation of a neighboring vacancy on top. The achieved homogeneity of the grown NV centers will tremendously benefit quantum information and metrology applications.
Publisher: American Physical Society (APS)
Date: 16-10-2013
Publisher: Springer Science and Business Media LLC
Date: 13-03-2019
DOI: 10.1038/S41467-019-09219-5
Abstract: Characteristic for devices based on two-dimensional materials are their low size, weight and power requirements. This makes them advantageous for use in space instrumentation, including photovoltaics, batteries, electronics, sensors and light sources for long-distance quantum communication. Here we present a comprehensive study on combined radiation effects in Earth’s atmosphere on various devices based on these nanomaterials. Using theoretical modeling packages, we estimate relevant radiation levels and then expose field-effect transistors, single-photon sources and monolayers as building blocks for future electronics to γ -rays, protons and electrons. The devices show negligible change in performance after the irradiation, suggesting robust suitability for space use. Under excessive γ -radiation, however, monolayer WS 2 shows decreased defect densities, identified by an increase in photoluminescence, carrier lifetime and a change in doping ratio proportional to the photon flux. The underlying mechanism is traced back to radiation-induced defect healing, wherein dissociated oxygen passivates sulfur vacancies.
Publisher: American Physical Society (APS)
Date: 08-04-2015
Publisher: IOP Publishing
Date: 08-04-2015
Publisher: American Physical Society (APS)
Date: 18-08-2017
Publisher: American Chemical Society (ACS)
Date: 12-12-2016
Publisher: American Physical Society (APS)
Date: 31-08-2017
Publisher: American Physical Society (APS)
Date: 25-11-2008
Publisher: Springer Science and Business Media LLC
Date: 21-11-2018
Publisher: American Physical Society (APS)
Date: 21-08-2015
Publisher: The Optical Society
Date: 09-2010
Publisher: Elsevier BV
Date: 07-2013
Publisher: Springer Science and Business Media LLC
Date: 08-05-2010
Publisher: Springer Science and Business Media LLC
Date: 30-08-2016
DOI: 10.1038/NCOMMS12660
Abstract: The nitrogen-vacancy (NV) centre in diamond is emerging as a promising platform for solid-state quantum information processing and nanoscale metrology. Of interest in these applications is the manipulation of the NV charge, which can be attained by optical excitation. Here, we use two-colour optical microscopy to investigate the dynamics of NV photo-ionization, charge diffusion and trapping in type-1b diamond. We combine fixed-point laser excitation and scanning fluorescence imaging to locally alter the concentration of negatively charged NVs, and to subsequently probe the corresponding redistribution of charge. We uncover the formation of spatial patterns of trapped charge, which we qualitatively reproduce via a model of the interplay between photo-excited carriers and atomic defects. Further, by using the NV as a probe, we map the relative fraction of positively charged nitrogen on localized optical excitation. These observations may prove important to transporting quantum information between NVs or to developing three-dimensional, charge-based memories.
Publisher: Springer Science and Business Media LLC
Date: 27-01-2017
DOI: 10.1038/NCOMMS14000
Publisher: OSA
Date: 2018
Publisher: Springer Science and Business Media LLC
Date: 17-04-2011
DOI: 10.1038/NPHYS1969
Publisher: American Physical Society (APS)
Date: 03-03-2014
Publisher: American Physical Society (APS)
Date: 02-06-2014
Publisher: American Physical Society (APS)
Date: 10-04-2009
Publisher: American Association for the Advancement of Science (AAAS)
Date: 02-10-2020
Abstract: We unravel the mystery of mechanically decoupled defect centers in hexagonal boron nitride.
Publisher: American Chemical Society (ACS)
Date: 13-02-2017
DOI: 10.1021/ACS.NANOLETT.6B04544
Abstract: Nanomechanical sensors and quantum nanosensors are two rapidly developing technologies that have erse interdisciplinary applications in biological and chemical analysis and microscopy. For ex le, nanomechanical sensors based upon nanoelectromechanical systems (NEMS) have demonstrated chip-scale mass spectrometry capable of detecting single macromolecules, such as proteins. Quantum nanosensors based upon electron spins of negatively charged nitrogen-vacancy (NV) centers in diamond have demonstrated erse modes of nanometrology, including single molecule magnetic resonance spectroscopy. Here, we report the first step toward combining these two complementary technologies in the form of diamond nanomechanical structures containing NV centers. We establish the principles for nanomechanical sensing using such nanospin-mechanical sensors (NSMS) and assess their potential for mass spectrometry and force microscopy. We predict that NSMS are able to provide unprecedented AC force images of cellular biomechanics and to not only detect the mass of a single macromolecule but also image its distribution. When combined with the other nanometrology modes of the NV center, NSMS potentially offer unparalleled analytical power at the nanoscale.
Publisher: American Physical Society (APS)
Date: 12-06-2012
Publisher: American Physical Society (APS)
Date: 03-05-2012
Publisher: American Physical Society (APS)
Date: 28-07-2014
Publisher: Elsevier BV
Date: 06-2021
Publisher: Springer Science and Business Media LLC
Date: 23-06-2013
Abstract: Electron and nuclear spins associated with point defects in insulators are promising systems for solid-state quantum technology. The electron spin is usually used for readout and addressing, and nuclear spins are used as exquisite quantum bits and memory systems. With these systems, single-shot readout of single nuclear spins as well as entanglement, aided by the electron spin, have been shown. Although the electron spin in this ex le is essential for readout, it usually limits the nuclear spin coherence, leading to a quest for defects with spin-free ground states. Here, we isolate a hitherto unidentified defect in diamond and use it at room temperature to demonstrate optical spin polarization and readout with exceptionally high contrast (up to 45%), coherent manipulation of an in idual excited triplet state spin, and coherent nuclear spin manipulation using the triplet electron spin as a metastable ancilla. We demonstrate nuclear magnetic resonance and Rabi oscillations of the uncoupled nuclear spin in the spin-free electronic ground state. Our study demonstrates that nuclei coupled to single metastable electron spins are useful quantum systems with long memory times, in spite of electronic relaxation processes.
Publisher: eLife Sciences Publications, Ltd
Date: 04-12-2017
DOI: 10.7554/ELIFE.26349
Abstract: Neurosecretory centers in animal brains use peptidergic signaling to influence physiology and behavior. Understanding neurosecretory center function requires mapping cell types, synapses, and peptidergic networks. Here we use transmission electron microscopy and gene expression mapping to analyze the synaptic and peptidergic connectome of an entire neurosecretory center. We reconstructed 78 neurosecretory neurons and mapped their synaptic connectivity in the brain of larval Platynereis dumerilii, a marine annelid. These neurons form an anterior neurosecretory center expressing many neuropeptides, including hypothalamic peptide orthologs and their receptors. Analysis of peptide-receptor pairs in spatially mapped single-cell transcriptome data revealed sparsely connected networks linking specific neuronal subsets. We experimentally analyzed one peptide-receptor pair and found that a neuropeptide can couple neurosecretory and synaptic brain signaling. Our study uncovered extensive networks of peptidergic signaling within a neurosecretory center and its connection to the synaptic brain.
Publisher: Walter de Gruyter GmbH
Date: 30-08-2019
Abstract: The nitrogen-vacancy (NV) color center in diamond has rapidly emerged as an important solid-state system for quantum information processing. Whereas in idual spin registers have been used to implement small-scale diamond quantum computing, the realization of a large-scale device requires the development of an on-chip quantum bus for transporting information between distant qubits. Here, we propose a method for coherent quantum transport of an electron and its spin state between distant NV centers. Transport is achieved by the implementation of spatial stimulated adiabatic Raman passage through the optical control of the NV center charge states and the confined conduction states of a diamond nanostructure. Our models show that, for two NV centers in a diamond nanowire, high-fidelity transport can be achieved over distances of order hundreds of nanometers in timescales of order hundreds of nanoseconds. Spatial adiabatic passage is therefore a promising option for realizing an on-chip spin quantum bus.
Publisher: American Chemical Society (ACS)
Date: 31-05-2019
DOI: 10.1021/ACS.NANOLETT.9B01402
Abstract: The precise measurement of mechanical stress at the nanoscale is of fundamental and technological importance. In principle, all six independent variables of the stress tensor, which describe the direction and magnitude of compression/tension and shear stress in a solid, can be exploited to tune or enhance the properties of materials and devices. However, existing techniques to probe the local stress are generally incapable of measuring the entire stress tensor. Here, we make use of an ensemble of atomic-sized in situ strain sensors in diamond (nitrogen-vacancy defects) to achieve spatial mapping of the full stress tensor, with a submicrometer spatial resolution and a sensitivity of the order of 1 MPa (10 MPa) for the shear (axial) stress components. To illustrate the effectiveness and versatility of the technique, we apply it to a broad range of experimental situations, including mapping the stress induced by localized implantation damage, nanoindents, and scratches. In addition, we observe surprisingly large stress contributions from functional electronic devices fabricated on the diamond and also demonstrate sensitivity to deformations of materials in contact with the diamond. Our technique could enable in situ measurements of the mechanical response of diamond nanostructures under various stimuli, with potential applications in strain engineering for diamond-based quantum technologies and in nanomechanical sensing for on-chip mass spectroscopy.
Publisher: Walter de Gruyter GmbH
Date: 20-07-2019
Abstract: The nitrogen-vacancy (NV) center in diamond is a widely utilized system due to its useful quantum properties. Almost all research focuses on the negative charge state (NV − ) and comparatively little is understood about the neutral charge state (NV 0 ). This is surprising as the charge state often fluctuates between NV 0 and NV − during measurements. There are potentially under-utilized technical applications that could take advantage of NV 0 , either by improving the performance of NV 0 or utilizing NV − directly. However, the fine structure of NV 0 has not been observed. Here, we rectify this lack of knowledge by performing magnetic circular dichroism measurements that quantitatively determine the fine structure of NV 0 . The observed behavior is accurately described by spin-Hamiltonians in the ground and excited states with the ground state yielding a spin-orbit coupling of λ = 2.24 ± 0.05 GHz and a orbital g -factor of 0.0186 ± 0.0005. The reasons why this fine structure has not been previously measured are discussed and strain-broadening is concluded to be the likely reason.
Publisher: American Chemical Society (ACS)
Date: 13-08-2014
DOI: 10.1021/NL501841D
Abstract: The negatively charged nitrogen-vacancy (NV(-)) center in diamond is at the frontier of quantum nanometrology and biosensing. Recent attention has focused on the application of high-sensitivity thermometry using the spin resonances of NV(-) centers in nanodiamond to subcellular biological and biomedical research. Here, we report a comprehensive investigation of the thermal properties of the center's spin resonances and demonstrate an alternate all-optical NV(-) thermometry technique that exploits the temperature dependence of the center's optical Debye-Waller factor.
Publisher: Springer Science and Business Media LLC
Date: 13-09-2018
Publisher: Elsevier BV
Date: 02-2010
Publisher: OSA
Date: 2015
Publisher: OSA
Date: 2017
Publisher: AIP Publishing
Date: 14-07-2014
DOI: 10.1063/1.4890096
Abstract: Key to future spintronics and spin-based information processing technologies is the generation, manipulation, and detection of spin polarization in a solid state platform. Here, we theoretically explore an alternative route to spin injection via the use of dynamically polarized nitrogen-vacancy (NV) centers in diamond. We focus on the geometry where carriers and NV centers are confined to proximate, parallel layers and use a “trap-and-release” model to calculate the spin cross-relaxation probabilities between the charge carriers and neighboring NV centers. We identify near-unity regimes of carrier polarization depending on the NV spin state, applied magnetic field, and carrier g-factor. In particular, we find that unlike holes, electron spins are distinctively robust against spin-lattice relaxation by other, unpolarized paramagnetic centers. Further, the polarization process is only weakly dependent on the carrier hopping dynamics, which makes this approach potentially applicable over a broad range of temperatures.
Start Date: 2017
End Date: 12-2021
Amount: $360,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 05-2022
End Date: 05-2024
Amount: $561,297.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2017
End Date: 02-2021
Amount: $449,500.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2023
End Date: 07-2023
Amount: $918,945.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 12-2018
Amount: $223,039.00
Funder: Australian Research Council
View Funded Activity