Quantum Electronic Devices

Welcome to the web page of the Quantum Electronic Devices group in UNSW's School of Physics

The Quantum Electronic Devices group is part of the Condensed Matter department in UNSW's School of Physics in the heart of Sydney. We are a key laboratory in the Australian Research Council Centre of Excellence for Future Low Energy Electronics Technologies.

Our research examines the fundamental properties of low dimensional systems realised in advanced semiconductor devices, and the development of new semiconductor and superconducting devices.

New: Scientia PhD Scholarship - A hole new spin on Quantum Information


A generously funded Scientia PhD Scholarship is available at the University of New South Wales in Sydney, Australia. This project in experimental quantum science will study holes in semiconductor quantum dots, an area in which UNSW is a world leader. Even though your iphone contains billions of p-type transistors, their quantum properties are only now being explored. Holes in quantum dots are attracting great attention because their spins can be controlled very easily with electric fields, rather than the conventional and slow approach with magnetic fields. This makes them very attractive for spintronics and quantum information applications: make it fast, make it coherent – make it with holes! The four year scholarship covers all university fees, provides a $40k annual living allowance, and up to an additional $10k per annum for support and mentoring.

Prospective applicants should contact Alex.Hamilton@unsw.edu.au by 6th July 2018.
Click here to submit your application

New: Scientia Postdoctoral Fellowships - UNSW


We are also looking for applications for postdoctoral Fellows to work on topological materials or spin-orbit physics in nanostructures. Full details of the application procedure are on the web at http://external-careers.jobs.unsw.edu.au/cw/en/job/493741/2019-unsw-scientia-fellowships

For general information about the scheme, including guidelines and FAQs please visit: https://www.2025.unsw.edu.au/apply/unsw-scientia-fellowship-faqs


28 Jun 2018
Another paper accepted for Physical Review Letters: "Multiband Mechanism for the Sign Reversal of Coulomb Drag Observed in Double Bilayer Graphene Heterostructures" by M. Zarenia, A.R. Hamilton, F.M. Peeters, and D. Neilson is a theory paper with our colleagues explaining the unexpected experimental observations of negative Coulomb drag reported by two separate research groups in Colombia and University of Texas (Austin). A preprint is available here: https://arxiv.org/abs/1806.10732
27 Jun 2018
Feixiang's paper, studying how the van der Waals crystal Tungsten Ditelluride changes its electronic structure from a 3D Weyl semimetal as it is mane into nanometer thick flakes, has been accepted for Physical Review B: "Thickness dependent electronic structure in WTe2 thin films", Fei-Xiang Xiang, Ashwin Srinivasan, Oleh Klochan, Shi-Xue Dou, Alex R. Hamilton, and Xiao-Lin Wang. A preprint is available here: https://arxiv.org/abs/1703.02741
22 Jun 2018
Elizabeth and Ashwin's paper reporting "Electrical control of the Zeeman spin splitting in two-dimensional hole systems" has been accepted for publication in Physical Review Letters! Well done all!
"Electrical control of the Zeeman spin splitting in two-dimensional hole systems", Elizabeth Marcellina, Ashwin Srinivasan, Dmitry Miserev, Andrew Croxall, David Ritchie, Ian Farrer, Oleg Sushkov, Dimitrie Culcer, Alex Hamilton. A preprint is available here: https://arxiv.org/abs/1806.10817
1 May 2018
Cheng Tan from Lan Wang's group at RMIT is visiting us to perform magnetoresistance measurements of 2D van-der Waals heterostructure devices.
17 Apr 2018
Congratulations to Ian Thorvaldson on winning the Physics Staff Prize for Physics I.
10 Apr 2018
Daisy has been invited to the 4th Silk Road International Symposium for Distinguished Young Scholars to be held at Xi'an Jiaotong University (XJTU) from April 11-15, 2018
12 Mar 2018
Welcome to new Honours student Isaac Vorreiter.
5 Mar 2018
Matt and Alex are giving talks at the 2018 APS March meeting of the American Physical Society in Los Angeles.
28 Feb 2018
Daisy is off to Japan, to make some new samples at Tohuku university.
30 Jan 2018
Daisy is presenting an invited talk at the 2018 International Conference on Nanoscience and Nanotechnology in Wollongong. Feixiang, Matt and Scott are each giving oral talks as well.
14 Jan 2018
Scott and Roy's beautiful work studying artificial hole atoms made of silicon quantum dots is on the preprint server. The work, part of our collaboration with Andrew Dzurak's group, shows artificial atoms made using one to 8 holes, where we can see the atomic orbitals filling up according to Hund's rules, and even determine the spin states - really cool. "Spin filling and orbital structure of the first six holes in a silicon metal-oxide-semiconductor quantum dot", S. D. Liles, R. Li, C. H. Yang, F. E. Hudson, M. Veldhorst, A. S. Dzurak, A. R. Hamilton, https://arxiv.org/abs/1801.04494.
24 Jan 2018
Congratulations to our collaborators Golrokh Akhgar, Daniel Creedon and all the team on the diamond project, whose experiments measuring the spin splitting and interface roughness for two-dimensional holes in surface conducting diamond have just appeared in Applied Physics Letters, and been selected as the cover article:
g-factor and well width variations for the two-dimensional hole gas in surface conducting diamond, G. Akhgar, D.L. Creedon, L.H. Willems van Beveren, A. Stacey, D.I. Hoxley, J.C. McCallum, L. Ley, A.R. Hamilton, and C.I. Pakes, Appl. Phys. Lett. 112, 042102 (2018); https://doi.org/10.1063/1.5010800
8 Jan 2018
Karina, Matt and Feixiang have been in Canberra at the 2018 Summer School on Topological Matter.
16 November 2017
Congratulations to Dr. Elizabeth Marcellina !
30 October 2017
The 2017 Gordon Godfrey Workshop on Spins and Strong Correlations will be held at UNSW from Monday 30th October – Friday 3rd November, with an impressive line-up of leading national and international speakers.
The workshop is FREE, and we are particularly encouraging Honours students, Masters/PhD, postdocs and ECRs to attend. There will also be an evening poster session for which we are encouraging submissions. We look forward to seeing you there.
27 September 2017
Some of UNSW's first year science students have been having fun measuring the Quantum Hall Effect in the QED group research labs under the watchful supervision of Karina Hudson, a PhD student in the QED group. The students used a helium-3 refrigerator to cool ultra-high quality gallium arsenide semiconductor chips to -273.4°C (0.25 degrees above absolute zero), and a superconducting magnet to study the Hall effect. The chips contain a thin (two-dimensional) sheet of highly mobile electrons, and at these low temperatures the students confirmed that the Hall resistance develops flat plateaus, where the Hall resistance depends only on the electron charge and Planck's constant, while the resistivity drops to zero. The unexpected discovery of the quantum Hall effect resulted in the 1985 Nobel Prize in Physics (and the fractional quantum Hall effect resulted in the 1998 Nobel Prize in Physics).
22 August 2017
Welcome to new group member Jonathan Ashlea-Alava, who joins us from Spain to start his PhD.
14 August 2017
Congratulations to Dima and Ashwin, whose combined theory and experimental paper resolving a 10-year old mystery has just been accepted into Physical Review Letters.
More than a decade ago QED researchers showed that the Zeeman splitting of holes in 1D wires was much larger if the magnetic field is applied along the wire than perpendicular to it, and this result was later confirmed by several other experimental groups. The anisotropic Zeeman splitting is a manifestation of the spin-orbit interaction, however, the mechanism of the effect has remained unclear in spite of a decade of intensive experimental and theoretical work. In the new work Dima Miserev and Oleg Sushkov show that this anisotropy is due to a new contribution to the Zeeman spin splitting that has previously been overlooked. A preprint is available here:
Mechanisms for strong anisotropy of in-plane g-factors in hole based quantum point contacts, D. S. Miserev, A. Srinivasan, I. Farrer, D. A. Ritchie, A. R. Hamilton, and O. P. Sushkov, https://arxiv.org/abs/1612.00572.
20 July 2017
Welcome to new QED group member Frederico Martins, who joins us from the Niels Bohr Institue in Copenhagen.
30 June 2017
A generously funded Scientia Scholarship is available to for a PhD project to study hole quantum dots.
The scholarship is fully funded for 4 years (including all university tuition fees, AUS$40k (US$30k) annually for living expenses, and an additional research/travel budget), and is open to applicants from any nationality.
The research project will investigate hole spins in quantum dots. In the past decade intense research has been devoted in trapping electrons trapped in semiconductor quantum dots, initially to study the fundamental properties of artificial atoms, and subsequently to use the spin of the electrons as the basis for quantum information technologies.
To date almost all research has focussed on the properties of electrons in semiconductor quantum dots. However very recent theoretical work suggests that that using positively charged semiconductor holes, rather than negatively charged electrons, may bring significant advantages – as well revealing much unexplored new physics. This is because of the much stronger spin-orbit interaction that exists in holes than electrons, allowing the hole spins to be manipulated simply by applying an electric field. The PhD candidate will study holes trapped in semiconductor quantum dots, to perform all electrical control of hole spins, and to test if holes can make good quantum bits. Experiments will be conducted at ultra-low temperatures, using ultra-low noise electrical measurement and control techniques.
The project is a collaborative effort between Scientia Professor Alex Hamilton in the Department of Physics and Scientia Professor Andrew Dzurak in the department of Electrical Engineering & Telecommunications.
Given the generous stipend and project funding, applicants are expected to have a first class academic record and preferably at least one peer reviewed publication. Details of how to apply are here: http://www.2025.unsw.edu.au/apply/scientia-phd-scholarships/hole-spins-quantum-dots
Prospective applicants must contact Alex.Hamilton@unsw.edu.au by 20 July 2017.
8 June 2017
Four fridges cold! We have all four dilution fridges cold, running lots of cool experiments.
5 May 2017
Jo-Tzu and Elizabeth's paper on the theory of spin-bloackade of holes in quantum dots been accepted for publication in PRB: "Spin blockade in hole quantum dots: Tuning exchange electrically and probing Zeeman interactions", J.T. Hung, E. Marcellina, B. Wang, A. R. Hamilton, and D. Culcer, Phys. Rev. B 95, 195316 (2017), https://doi.org/10.1103/PhysRevB.95.195316.
10 Apr 2017
Scott and Daisy have gone to Denmark to conduct experiments at the Centre for Quantum Devices in the Niels Bohr Institute at the University of Copenhagen. Have a great trip!
5 Apr 2017
Well done to Ashwin, Dima and Karina; their paper showing that we can detect the signatures of Rashba and Dresselhaus spin-orbit interactions in hole quantum point contacts, and even control their interplay by changing the substrate orientation, has just been published in Physical Review Letters: "Detection and Control of Spin-Orbit Interactions in a GaAs Hole Quantum Point Contact", A. Srinivasan, D. S. Miserev, K. L. Hudson, O. Klochan, K. Muraki, Y. Hirayama, D. Reuter, A. D. Wieck, O. P. Sushkov, and A. R. Hamilton, Phys. Rev. Lett. 118, 146801 (2017). https://doi.org/10.1103/PhysRevLett.118.146801 with a preprint here: https://arxiv.org/abs/1703.04233.
1 Feb 2017
The new fridge, which we are thinking will either be called Dreadnought or Leviathan, cools below 7mK.
17 Jan 2017
Congratulations to Elizabeth on her first paper! Her work on the theory of 2D hole systems in heterojunction devices in different material systems has been accepted for PRB and chosen as an Editor's choice: "Spin-orbit interactions in inversion-asymmetric two-dimensional hole systems: A variational analysis", E. Marcellina, A. R. Hamilton, R. Winkler, and Dimitrie Culcer, to appear in Phys Rev B. Preprint is here https://arxiv.org/abs/1604.08759.
23 Jan 2017
Installation of our new fridge has started - see BlueForsxLDFridgeInstallationTimelapse for details.
24 Nov 2016
Well done to Daisy, whose paper reporting the first measurements of anisotropic spin blockade in a spin-3/2 heavy hole system has just been accepted for publication in Nano Letters: D.Q. Wang, O. Klochan, J-T Hung, D. Culcer, I. Farrer, D.A. Ritchie, and .R. Hamilton, Anisotropic Pauli Spin Blockade of Holes in a GaAs Double Quantum Dot, Nano Lett., accepted: November 24, (2016). http://dx.doi.org/10.1021/acs.nanolett.6b03752
8 Sept 2016
Congratulations to Oleh Klochan, Oleg Sushkov, Dimi Culcer and Alex Hamilton in the School of Physics, as well as Jan Seidel and Nagarajan Valanoor in the School of Materials Science and Engineering, on the successful ARC Centre of Excellence in Future Low Energy Electronics Technologies (FLEET). The Centre will receive $33M in ARC funding over the next 7 years. It is headquartered at Monash University, with a major presence at UNSW, and will develop the scientific foundations for fundamentally new types of electronic conduction based on topological properties of matter, with potential for future low energy electronics technologies.
18 July 2016
Well done to Ashwin, Karina and Dima - their paper reporting a direct measurement of the magnitude and sign of the g-factor of holes in a quantum point contact has just appeared as a Rapid Communication in Physical Review B: A. Srinivasan, K. L. Hudson, D. Miserev, L. A. Yeoh, O. Klochan, K. Muraki, Y. Hirayama, O. P. Sushkov, and A. R. Hamilton, Electrical control of the sign of the g factor in a GaAs hole quantum point contact, Phys. Rev. B 94, 041406(R) (2016). http://dx.doi.org/10.1103/PhysRevB.94.041406
8 July 2016
Congratulations to Daisy Wang and Oleh Klochan - their paper on a novel double layer gate architecture for making hole quantum dots has just been published: D Q Wang, A R Hamilton, I Farrer, D A Ritchie and O Klochan, Double-layer-gate architecture for few-hole GaAs quantum dots, Nanotechnology 27, 334001 (2016). http://dx.doi.org/10.1088/0957-4484/27/33/334001
17 May 2016
Congratulations to Golrokh Akhgar (LaTrobe), Oleh Klochan (UNSW) and Chris Pakes' diamond team at LaTrobe University: their paper reporting that it is possible to tune the strength of the spin-orbit interaction of 2D holes in surface conducting diamond transistors, has just been accepted by Nano Letters: Strong and Tunable Spin–Orbit Coupling in a Two-Dimensional Hole Gas in Ionic-Liquid Gated Diamond Devices, G. Akhgar, O. Klochan, L.H. Willems van Beveren, M.T. Edmonds, F. Maier, B.J. Spencer, J.C. McCallum, L. Ley, A.R. Hamilton, and C.I. Pakes, Nano Letters (in press, 2016). See http://dx.doi.org/10.1021/acs.nanolett.6b01155.
25 April 2016
Congratulations to Tommy Li and LaReine Yeoh - their paper reporting the observation of non-adiabatic spin dynamics (equivalent to a non-abelian Berry phase) in a 2D hole system has just been accepted for publication: Manifestation of a non-Abelian Berry phase in a p-type semiconductor system, T. Li, L.A. Yeoh, A. Srinivasan, O. Klochan, D. A. Ritchie, M.Y. Simmons, O.P. Sushkov, and A.R. Hamilton, Physical Review B 93, 205424 (2016). See http://dx.doi.org/10.1103/PhysRevB.93.205424
11 Mar 2016
Elizabeth Marcellina is off to Baltimore to present her work at the 2016 March Meeting of the American Physical Society.
29 Feb 2016
Welcome to new Honours student Jarrod Adam.
31 Jan 2016
Congratulations to Dr. Daisy Wang !
28 Jan 2016
Congratulations to Matt Rendell, whose paper on magnetic focussing of holes has been selected by the Editorial Board as one of the Semiconductor Science and Technology Highlights of 2015.
18 Jan 2016
Welcome to two new group members: Honours student Yonatan, and undergraduate vacation scholar Isaac.
7 Jan 2016
Congratulations to Dr. Roy Li !

Topic revision: r83 - 29 Jun 2018, AlexHamilton