ORCID Profile
0000-0002-2837-275X
Current Organisation
University of New South Wales Canberra at ADFA
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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)
Electronic and Magnetic Properties of Condensed Matter; Superconductivity | Condensed Matter Physics | Nanoelectronics | Functional Materials | Nanotechnology | Nanomaterials | Nanotechnology | Nanoscale Characterisation | Degenerate Quantum Gases and Atom Optics | Condensed Matter Physics—Electronic And Magnetic Properties; |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in Engineering | Commercial Energy Conservation and Efficiency | Management of Greenhouse Gas Emissions from Information and Communication Services | Integrated Circuits and Devices | Integrated circuits and devices | Physical sciences | Expanding Knowledge in Technology
Related Links
Publications
Crystallographic anisotropy of the Zeeman splitting in 1D hole quantum wires
Publisher: Elsevier BV
Date: 02-2010
Fabrication and characterisation of an induced ambipolar device on AlGaAs/GaAs Heterostructures
Publisher: IEEE
Date: 12-2010
The influence of small-angle scattering on ballistic transport in quantum dots
Publisher: IEEE
Date: 12-2012
The 1D g-factor and 0.7 anomaly in QPCs with independent control over density
Publisher: IEEE
Date: 12-2012
AlGaAs/GaAs single electron transistor fabricated without modulation doping
Publisher: AIP Publishing
Date: 15-03-0011
DOI: 10.1063/1.3358388
Abstract: We have fabricated a quantum dot single electron transistor, based on AlGaAs/GaAs heterojunction without modulation doping, which exhibits clear and stable Coulomb blockade oscillations. The temperature dependence of the Coulomb blockade peak line shape is well described by standard Coulomb blockade theory in the quantum regime. Bias spectroscopy measurements have allowed us to directly extract the charging energy, and showed clear evidence of excited state transport, confirming that in idual quantum states in the dot can be resolved.
Gate voltage dependent Rashba spin splitting in hole transverse magnetic focusing
Publisher: American Physical Society (APS)
Date: 15-06-2022
You need another gate, mate': G-factor engineering in quantum wires and wrap-gated nanowires
Publisher: IEEE
Date: 12-2012
Zeeman Splitting in Ballistic Hole Quantum Wires
Publisher: American Physical Society (APS)
Date: 11-07-2006
Erratum: Manifestation of a non-Abelian Berry phase in a p -type semiconductor system (Physical Review B - Condensed Matter and Materials Physics (2016) 93 (205424) DOI: 10.1103/PhysRevB.93.205424)
Publisher: American Physical Society (APS)
Date: 13-06-2016
Impact of Small-Angle Scattering on Ballistic Transport in Quantum Dots
Publisher: American Physical Society (APS)
Date: 11-05-2012
Screening long-range Coulomb interactions in 2D hole systems using a bilayer heterostructure
Publisher: Elsevier BV
Date: 03-2008
Mapping the anisotropy of the Zeeman spin splitting of one-dimensional heavy holes in a GaAs quantum point contact
Publisher: IEEE
Date: 12-2014
(100) GaAs/Al(x)Ga(1-x)As heterostructures for Zeeman spin splitting studies of hole quantum wires
Publisher: Elsevier BV
Date: 05-2011
Electrical control of the sign of the g factor in a GaAs hole quantum point contact
Publisher: American Physical Society (APS)
Date: 18-07-2016
Fabrication and characterisation of gallium arsenide ambipolar quantum point contacts
Publisher: AIP Publishing
Date: 04-05-2015
DOI: 10.1063/1.4918934
Abstract: We show that ballistic one-dimensional channels can be formed in an ambipolar device fabricated on a high mobility Al0.34Ga0.66As/GaAs heterostructure. Both electron and hole quantised conductances can be measured in the same one-dimensional channel. We have used this device to compare directly the subband spacings of the two charge carriers in the same confining potential and used this to compare the electron and hole effective masses.
New signatures of the spin gap in quantum point contacts
Publisher: Springer Science and Business Media LLC
Date: 04-01-2021
DOI: 10.1038/S41467-020-19895-3
Abstract: One dimensional semiconductor systems with strong spin-orbit interaction are both of fundamental interest and have potential applications to topological quantum computing. Applying a magnetic field can open a spin gap, a pre-requisite for Majorana zero modes. The spin gap is predicted to manifest as a field dependent dip on the first 1D conductance plateau. However, disorder and interaction effects make identifying spin gap signatures challenging. Here we study experimentally and numerically the 1D channel in a series of low disorder p-type GaAs quantum point contacts, where spin-orbit and hole-hole interactions are strong. We demonstrate an alternative signature for probing spin gaps, which is insensitive to disorder, based on the linear and non-linear response to the orientation of the applied magnetic field, and extract a spin-orbit gap Δ E ≈ 500 μ eV. This approach could enable one-dimensional hole systems to be developed as a scalable and reproducible platform for topological quantum applications.
Anisotropic Pauli Spin Blockade of Holes in a GaAs Double Quantum Dot
Publisher: American Chemical Society (ACS)
Date: 12-2016
DOI: 10.1021/ACS.NANOLETT.6B03752
Abstract: Electrically defined semiconductor quantum dots are attractive systems for spin manipulation and quantum information processing. Heavy-holes in both Si and GaAs are promising candidates for all-electrical spin manipulation, owing to the weak hyperfine interaction and strong spin-orbit interaction. However, it has only recently become possible to make stable quantum dots in these systems, mainly due to difficulties in device fabrication and stability. Here, we present electrical transport measurements on holes in a gate-defined double quantum dot in a GaAs/Al
Fabrication and characterization of an undoped GaAs single hole transistor
Publisher: IEEE
Date: 12-2010
Conductance quantization and the 0.7×2e2/h conductance anomaly in one-dimensional hole systems
Publisher: AIP Publishing
Date: 02-01-2006
DOI: 10.1063/1.2161814
Abstract: We have studied ballistic transport in a one-dimensional (1D) channel formed using surface gate techniques on a back-gated, high-mobility, bilayer two-dimensional hole system. At millikelvin temperatures, robust conductance quantization is observed in the quantum wire formed in the top layer of the bilayer system, without the gate instabilities that have h ered previous studies of 1D hole systems. Using source drain bias spectroscopy, we have measured the 1D subband spacings, which are 5–10 times smaller than in comparable GaAs electron systems, but 2–3 times larger than in previous studies of 1D holes. We also report the first observation of the anomalous conductance plateau at G=0.7×2e2∕h in a 1D hole system.
Spin-Orbit Interaction in a Two-Dimensional Hole Gas at the Surface of Hydrogenated Diamond
Publisher: American Chemical Society (ACS)
Date: 08-12-2015
DOI: 10.1021/NL502081Y
Abstract: Hydrogenated diamond possesses a unique surface conductivity as a result of transfer doping by surface acceptors. Yet, despite being extensively studied for the past two decades, little is known about the system at low temperature, particularly whether a two-dimensional hole gas forms at the diamond surface. Here we report that (100) diamond, when functionalized with hydrogen, supports a p-type spin-3/2 two-dimensional surface conductivity with a spin-orbit interaction of 9.74 ± 0.1 meV through the observation of weak antilocalization effects in magneto-conductivity measurements at low temperature. Fits to 2D localization theory yield a spin relaxation length of 30 ± 1 nm and a spin-relaxation time of ∼ 0.67 ± 0.02 ps. The existence of a 2D system with spin orbit coupling at the surface of a wide band gap insulating material has great potential for future applications in ferromagnet-semiconductor and superconductor-semiconductor devices.
Double-layer-gate architecture for few-hole GaAs quantum dots
Publisher: IOP Publishing
Date: 08-07-2016
DOI: 10.1088/0957-4484/27/33/334001
Abstract: We report the fabrication of single and double hole quantum dots using a double-layer-gate design on an undoped accumulation mode [Formula: see text]/GaAs heterostructure. Electrical transport measurements of a single quantum dot show varying addition energies and clear excited states. In addition, the two-level-gate architecture can also be configured into a double quantum dot with tunable inter-dot coupling.
Extreme Sensitivity of the Spin-Splitting and 0.7 Anomaly to Confining Potential in One-Dimensional Nanoelectronic Devices
Publisher: American Chemical Society (ACS)
Date: 08-2012
DOI: 10.1021/NL301566D
Abstract: Quantum point contacts (QPCs) have shown promise as nanoscale spin-selective components for spintronic applications and are of fundamental interest in the study of electron many-body effects such as the 0.7 × 2e(2)/h anomaly. We report on the dependence of the 1D Landé g-factor g and 0.7 anomaly on electron density and confinement in QPCs with two different top-gate architectures. We obtain g values up to 2.8 for the lowest 1D subband, significantly exceeding previous in-plane g-factor values in AlGaAs/GaAs QPCs and approaching that in InGaAs/InP QPCs. We show that g is highly sensitive to confinement potential, particularly for the lowest 1D subband. This suggests careful management of the QPC's confinement potential may enable the high g desirable for spintronic applications without resorting to narrow-gap materials such as InAs or InSb. The 0.7 anomaly and zero-bias peak are also highly sensitive to confining potential, explaining the conflicting density dependencies of the 0.7 anomaly in the literature.
Spin polarization and spin-dependent scattering of holes observed in transverse magnetic focusing
Publisher: American Physical Society (APS)
Date: 12-01-2023
Geometric Control of Universal Hydrodynamic Flow in a Two-Dimensional Electron Fluid
Publisher: American Physical Society (APS)
Date: 06-08-2021
Determining the stability and activation energy of Si acceptors in AlGaAs using quantum interference in an open hole quantum dot
Publisher: American Physical Society (APS)
Date: 17-04-2014
Landau level spin diode in a GaAs two dimensional hole system
Publisher: IOP Publishing
Date: 20-03-2015
Observation of the Kondo effect in a spin-3/2 hole quantum dot
Publisher: IEEE
Date: 12-2012
Conductance quantisation in an induced hole quantum wire
Publisher: AIP
Date: 2007
DOI: 10.1063/1.2730073
Effect of screening long-range Coulomb interactions on the metallic behavior in two-dimensional hole systems
Publisher: American Physical Society (APS)
Date: 13-05-2008
One-dimensional conduction properties of highly phosphorus-doped planar nanowires patterned by scanning probe microscopy
Publisher: American Physical Society (APS)
Date: 02-08-2007
Noncollinear Paramagnetism of a GaAs Two-Dimensional Hole System
Publisher: American Physical Society (APS)
Date: 03-12-2014
Detection and Control of Spin-Orbit Interactions in a GaAs Hole Quantum Point Contact
Publisher: American Physical Society (APS)
Date: 05-04-2017
Scaling of the Kondo zero-bias peak in a hole quantum dot at finite temperatures
Publisher: American Physical Society (APS)
Date: 14-05-2013
Ballistic induced hole quantum wires fabricated on a (1 0 0)-oriented AlGaAs/GaAs heterostructure
Publisher: Elsevier BV
Date: 02-2010
Observation of orientation- andk-dependent Zeeman spin-splitting in hole quantum wires on (100)-oriented AlGaAs/GaAs heterostructures
Publisher: IOP Publishing
Date: 24-03-2010
Ballistic transport in induced one-dimensional hole systems
Publisher: AIP Publishing
Date: 28-08-2006
DOI: 10.1063/1.2337525
Abstract: The authors have fabricated and studied a ballistic one-dimensional p-type quantum wire using an undoped AlGaAs∕GaAs heterostructure. The absence of modulation doping eliminates remote ionized impurity scattering and allows high mobilities to be achieved over a wide range of hole densities and, in particular, at very low densities where carrier-carrier interactions are strongest. The device exhibits clear quantized conductance plateaus with highly stable gate characteristics. These devices provide opportunities for studying spin-orbit coupling and interaction effects in mesoscopic hole systems in the strong interaction regime where rs& .
The reduced effective interaction parameter in closely spaced two-dimensional hole systems
Publisher: AIP
Date: 2009
DOI: 10.1063/1.3295372
Formation of Artificial Fermi Surfaces with a Triangular Superlattice on a Conventional Two-Dimensional Electron Gas
Publisher: American Chemical Society (ACS)
Date: 15-02-2023
The 0.7 anomaly in one-dimensional hole quantum wires
Publisher: IOP Publishing
Date: 04-2008
Fabrication of undoped AlGaAs/GaAs electron quantum dots
Publisher: IEEE
Date: 02-2010
The origin of gate hysteresis in p-type Si-doped AlGaAs/GaAs heterostructures
Publisher: IEEE
Date: 12-2012
Transport in disordered monolayer MoS2 nanoflakes-evidence for inhomogeneous charge transport
Publisher: IOP Publishing
Date: 22-08-2014
DOI: 10.1088/0957-4484/25/37/375201
Abstract: We study charge transport in a monolayer MoS2 nanoflake over a wide range of carrier density, temperature and electric bias. We find that the transport is best described by a percolating picture in which the disorder breaks translational invariance, breaking the system up into a series of puddles, rather than previous pictures in which the disorder is treated as homogeneous and uniform. Our work provides insight to a unified picture of charge transport in monolayer MoS2 nanoflakes and contributes to the development of next-generation MoS2-based devices.
A study of transport suppression in an undoped AlGaAs/GaAs quantum dot single-electron transistor
Publisher: IOP Publishing
Date: 25-11-2013
DOI: 10.1088/0953-8984/25/50/505302
Abstract: We report a study of transport blockade features in a quantum dot single-electron transistor, based on an undoped AlGaAs/GaAs heterostructure. We observe suppression of transport through the ground state of the dot, as well as negative differential conductance at finite source-drain bias. The temperature and magnetic field dependences of these features indicate the couplings between the leads and the quantum dot states are suppressed. We attribute this to two possible mechanisms: spin effects which determine whether a particular charge transition is allowed based on the change in total spin, and the interference effects which arise from coherent tunnelling of electrons in the quantum dot.
Fabrication and characterization of an induced GaAs single hole transistor
Publisher: AIP Publishing
Date: 03-2010
DOI: 10.1063/1.3336011
Abstract: We have fabricated and characterized a single hole transistor in an undoped AlGaAs-GaAs heterostructure. Our device consists of a p-type quantum dot, populated using an electric field rather than modulation doping. Low temperature transport measurements reveal periodic conductance oscillations due to Coulomb blockade. We find that the low frequency charge noise is comparable to that in modulation-doped GaAs single electron transistors (SETs), and an order of magnitude better than in silicon SETs.
Resistively Detected Nuclear Magnetic Resonance in n- and p-Type GaAs Quantum Point Contacts
Publisher: American Chemical Society (ACS)
Date: 13-07-2011
DOI: 10.1021/NL201211D
Abstract: We present resistively detected NMR measurements in induced and modulation-doped electron quantum point contacts, as well as induced hole quantum point contacts. While the magnitude of the resistance change and associated NMR peaks in n-type devices is in line with other recent measurements using this technique, the effect in p-type devices is too small to measure. This suggests that the hyperfine coupling between holes and nuclei in this type of device is much smaller than the electron hyperfine coupling, which could have implications in quantum information processing.
High electron mobility and low noise quantum point contacts in an ultra-shallow all-epitaxial metal gate GaAs/AlxGa1−xAs heterostructure
Publisher: AIP Publishing
Date: 09-08-2021
DOI: 10.1063/5.0053816
Abstract: The mobility of the two-dimensional electron gas (2DEG) in shallow GaAs/AlxGa1−xAs heterostructures is strongly suppressed by unwanted Coulomb scattering from surface charge, likely located in native surface oxides that form after the wafer is removed from the crystal growth system. Here, we show that this native surface oxide can be eliminated by growing an epitaxial aluminum gate before removing the wafer from the growth chamber. We fabricate accumulation mode devices on two wafers with nearly identical structures and growth conditions: one with an epitaxial aluminum gate 35 nm above the channel and another with an ex situ metal gate deposited on an aluminum oxide dielectric. Low temperature transport measurements show that the epitaxial gate design greatly reduces surface charge scattering, with up to 2.5× increase in mobility. Despite the ultra-shallow 2DEG (35 nm), the mobility remains high even at low carrier densities. Finally, we show that the epitaxial aluminum gate can be patterned to make nanostructures by fabricating a quantum point contact that shows robust and reproducible 1D conductance quantization, with extremely low charge noise.
Ultra‐Shallow All‐Epitaxial Aluminum Gate GaAs/AlxGa1−xAs Transistors with High Electron Mobility
Publisher: Wiley
Date: 19-08-2022
Abstract: The electron mobility in shallow GaAs/Al x Ga 1−x As heterostructures is strongly suppressed by charge wafer surface, which arises from native surface oxide layers formed when the wafer is removed from the crystal growth system. Here an in situ epitaxial aluminum gate, grown as part of the wafer, is used to eliminate surface charge scattering. Transmission electron microscope characterization shows that the in situ epitaxial aluminum is crystalline, and the wafer surface is free of native oxide. The influence of Al thickness and the use of different semiconductor wetting layers at the semiconductor‐aluminum interface are examined and correlated with electron mobility. The electron mobility is found to strongly depend on aluminum thickness. For 8 nm thick aluminum, the electron mobility is also influenced by the wetting layer, with aluminum grown on GaAs producing higher mobility compared to AlAs or Al 0.33 Ga 0.67 As wetting layers. The suppression of surface charge scattering in these all‐epitaxial devices allows for high mobilities across a wide density range despite the shallow conduction channel (35 nm below the gate). These measurements also provide a uniquely sensitive method of determining the electrical quality of the semiconductor–metal interface, relevant to the formation of hybrid semiconductor–superconductor devices.
Two-dimensional lateral surface superlattices in GaAs heterostructures with independent control of carrier density and modulation potential
Publisher: AIP Publishing
Date: 20-07-2020
DOI: 10.1063/5.0009462
Abstract: We present a double-layer design for two-dimensional lateral surface superlattice systems in GaAs-AlGaAs heterostructures. Unlike previous studies, our device (1) uses an in situ gate, which allows a very short period superlattice in high mobility, shallow heterostructures and (2) enables independent control of the carrier density and the superlattice modulation potential litude over a wide range. We characterize this device design using low-temperature magneto-transport measurements and show that the fabrication process caused minimal damage to the system. We demonstrate the tuning of potential modulation from weak (much smaller than Fermi energy) to strong (larger than the Fermi energy) regimes.
The interplay between one-dimensional confinement and two-dimensional crystallographic anisotropy effects in ballistic hole quantum wires
Publisher: IOP Publishing
Date: 15-04-2009
Using a Tunable Quantum Wire To Measure the Large out-of-Plane Spin Splitting of Quasi Two-Dimensional Holes in a GaAs Nanostructure
Publisher: American Chemical Society (ACS)
Date: 26-12-2013
DOI: 10.1021/NL303596S
Abstract: The out-of-plane g-factor g([perpendicular])(*) for quasi two-dimensional (2D) holes in a (100) GaAs heterostructure is studied using a variable width quantum wire. A direct measurement of the Zeeman splitting is performed in a magnetic field applied perpendicular to the 2D plane. We measure an out-of-plane g-factor up to g([perpendicular])(*) = 5, which is larger than previous optical studies of g([perpendicular])(*) and is approaching the long predicted but never experimentally verified out-of-plane g-factor of 7.2 for heavy holes.
Fabrication and characterization of few-hole quantum dots in undoped GaAs/AlGaAs heterostructures
Publisher: IEEE
Date: 12-2014
Quantum transport in one-dimensional GaAs hole systems
Publisher: Inderscience Publishers
Date: 2008
Ballistic transport in one-dimensional bilayer hole systems
Publisher: Elsevier BV
Date: 08-2006
Thickness-dependent electronic structure in WTe2 thin films
Publisher: American Physical Society (APS)
Date: 13-07-2018
Observation of the Kondo Effect in a Spin-3/2 Hole Quantum Dot
Publisher: American Physical Society (APS)
Date: 12-08-2011
Electrically controlled piezo-rotator for studying semiconductor nanostructures at milli-Kelvin temperatures and high magnetic fields
Publisher: IEEE
Date: 02-2010
Anisotropic Zeeman Splitting In Ballistic One-Dimensional Hole Systems
Publisher: AIP
Date: 2007
DOI: 10.1063/1.2730082
Ultra-shallow quantum dots in an undoped GaAs/AlGaAs two-dimensional electron gas
Publisher: AIP Publishing
Date: 11-03-2013
DOI: 10.1063/1.4795613
Abstract: We report quantum dots fabricated on very shallow 2-dimensional electron gases, only 30 nm below the surface, in undoped GaAs/AlGaAs heterostructures grown by molecular beam epitaxy. Due to the absence of dopants, an improvement of more than one order of magnitude in mobility (at 2 × 1011 cm−2) with respect to doped heterostructures with similar depths is observed. These undoped wafers can easily be gated with surface metallic gates patterned by e-beam lithography, as demonstrated here from single-level transport through a quantum dot showing large charging energies (up to 1.75 meV) and excited state energies (up to 0.5 meV).
Observation of the Kondo Effect in a Spin-3/2 Hole Quantum Dot
Publisher: AIP
Date: 2013
DOI: 10.1063/1.4848430
Transverse magnetic focussing of heavy holes in a (100) GaAs quantum well
Publisher: IOP Publishing
Date: 14-09-2015
Influence of surface states on quantum and transport lifetimes in high-quality undoped heterostructures
Publisher: American Physical Society (APS)
Date: 23-05-2013
Absorption enhancement of WS2 monolayer based on Si3N4 nanowires
Publisher: Optica Publishing Group
Date: 2020
Abstract: We show that the addition of an array of silicon nitride nanowire resonator can boost the absorbance of a monolayer of WS 2 from around 5-10% to 62% at the exciton wavelength of 620 nm.
Strong and tunable spin-orbit coupling in a two-dimensional hole gas in ionic-liquid gated diamond devices
Publisher: American Chemical Society (ACS)
Date: 26-05-2016
DOI: 10.1021/ACS.NANOLETT.6B01155
Abstract: Hydrogen-terminated diamond possesses due to transfer doping a quasi-two-dimensional (2D) hole accumulation layer at the surface with a strong, Rashba-type spin-orbit coupling that arises from the highly asymmetric confinement potential. By modulating the hole concentration and thus the potential using an electrostatic gate with an ionic-liquid dielectric architecture the spin-orbit splitting can be tuned from 4.6-24.5 meV with a concurrent spin relaxation length of 33-16 nm and hole sheet densities of up to 7.23 × 10(13) cm(-2). This demonstrates a spin-orbit interaction of unprecedented strength and tunability for a 2D hole system at the surface of a wide band gap semiconductor. With a spin relaxation length that is experimentally accessible using existing nanofabrication techniques, this result suggests that hydrogen-terminated diamond has great potential for the study and application of spin transport phenomena.
Fabrication of Undoped AlGaAs/GaAs Electron Quantum Dots
Publisher: AIP
Date: 2011
DOI: 10.1063/1.3666394
0.7 Structure and zero bias anomaly in one-dimensional hole systems
Publisher: Elsevier BV
Date: 03-2008
Fabrication and characterization of ambipolar devices on an undoped AlGaAs/GaAs heterostructure
Publisher: AIP Publishing
Date: 30-01-2012
DOI: 10.1063/1.3673837
Abstract: We have fabricated AlGaAs/GaAs heterostructure devices in which the conduction channel can be populated with either electrons or holes simply by changing the polarity of a gate bias. The heterostructures are entirely undoped, and carriers are, instead, induced electrostatically. We use these devices to perform a direct comparison of the scattering mechanisms of two-dimensional electrons (μpeak = 4 × 106 cm2/Vs) and holes (μpeak = 0.8 × 106 cm2/Vs) in the same conduction channel with nominally identical disorder potentials. We find significant discrepancies between electron and hole scattering, with the hole mobility being considerably lower than expected from simple theory.
0.7 Structure and zero bias anomaly in ballistic hole quantum wires
Publisher: American Physical Society (APS)
Date: 10-01-2008
Origin of gate hysteresis in p-type Si-doped AlGaAs/GaAs heterostructures
Publisher: American Physical Society (APS)
Date: 08-10-2012
Manifestation of a non-Abelian Berry phase in a p-type semiconductor system
Publisher: American Physical Society (APS)
Date: 17-05-2016
Overlapping-Gate Architecture for Silicon Hall Bar MOSFET Devices in the Low Electron Density and High Magnetic Field Regime
Publisher: Trans Tech Publications, Ltd.
Date: 09-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.700.93
Abstract: A common issue in low temperature measurements of enhancement-mode metal-oxide-semiconductor (MOS) field-effect transistors (FETs) in the low electron density regime is the high contact resistance dominating the device impedance. In that case a voltage bias applied across the source and drain contact of a Hall bar MOSFET will mostly fall across the contacts (and not across the channel) and therefore magneto-transport measurements become challenging. However, from a physical point of view, the study of MOSFET nanostructures in the low electron density regime is very interesting (impurity limited mobility [1], carrier interactions [2,3] and spin-dependent transport [4]) and it is therefore important to come up with solutions [5,6] that work around the problem of a high contact resistance in such devices (c.f. Fig. 1 (a)).
Piezoelectric rotator for studying quantum effects in semiconductor nanostructures at high magnetic fields and low temperatures
Publisher: AIP Publishing
Date: 11-2010
DOI: 10.1063/1.3502645
Abstract: We report the design and development of a piezoelectric s le rotation system, and its integration into an Oxford Instruments Kelvinox 100 dilution refrigerator, for orientation-dependent studies of quantum transport in semiconductor nanodevices at millikelvin temperatures in magnetic fields up to 10 T. Our apparatus allows for continuous in situ rotation of a device through & ° in two possible configurations. The first enables rotation of the field within the plane of the device, and the second allows the field to be rotated from in-plane to perpendicular to the device plane. An integrated angle sensor coupled with a closed-loop feedback system allows the device orientation to be known to within ±0.03° while maintaining the s le temperature below 100 mK.
Related Organisations
Related Funding Activities
Discovery Early Career Researcher Award - Grant ID: DE140100775
Start Date: 2014
End Date: 12-2017
Amount: $394,177.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE140100170
Start Date: 2014
End Date: 12-2017
Amount: $560,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE200100197
Start Date: 07-2020
End Date: 12-2021
Amount: $1,102,947.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE0989760
Start Date: 2009
End Date: 12-2010
Amount: $100,000.00
Funder: Australian Research Council
View Funded ActivityARC Centres Of Excellence - Grant ID: CE170100039
Start Date: 06-2017
End Date: 06-2024
Amount: $33,400,000.00
Funder: Australian Research Council
View Funded Activity