Quantum Electronic Devices

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


QED group May 2016

The QED group

The Quantum Electronic Devices group is part of the Condensed Matter department in UNSW's School of Physics in the heart of Sydney.
Our research examines the fundamental properties of low dimensional systems realised in advanced semiconductor devices, and the development of new semiconductor and superconducting devices.

What's new

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 !
3 Nov 2015
Grant success - the QED group and collaborators in the UK, Germany and New Zealand have won a $480,000 ARC grant to investigate the spin properties of holes in nanostructures. This is a real testament to the hard work of so many members of the group. Looks like it's Alex's shout...
12 Oct 2015
Fingers crossed for Ashwin Srinivasan, whose PhD has been selected as one of the two NSW representatives for the Australian Institute of Physics Bragg Medal for best PhD thesis.
5 Oct 2015
Well done to Roy Li and colleagues - their paper reporting the first observation of Pauli spin blockade of heavy holes in silicon has just appeared in Nano Letters! http://dx.doi.org/10.1021/acs.nanolett.5b02561. A preprint is available here.
14 Sept 2015
Well done to Matt! His undergraduate honours experiments on magnetic focussing of holes in a GaAs nanostructure device, performed with Oleh Klochan, has been published as an open access Fast Track Communication in Semiconductor Science and Technology: Transverse magnetic focussing of heavy holes in a (100) GaAs quantum well, M Rendell, O Klochan, A Srinivasan, I Farrer, D A Ritchie and A R Hamilton, Semicond. Sci. Technol. 30, 102001 (2015). See http://dx.doi.org/10.1088/0268-1242/30/10/102001
10 Aug 2015
Another paper: Giordano Scappucci has published a really nice study comparing the structural and electronic properties of delta doped layers in Germanium, using weak localisation to map out the wavefunction overlap between adjacent layers of dopants and compare with atom probe and theoretical simulations: Bottom-up assembly of metallic germanium, by Giordano Scappucci, W. M. Klesse, LaReine Yeoh, D. J. Carter, O. Warschkow, N.A. Marks, D.L. Jaeger, G. Capellini, M.Y. Simmons, and A.R. Hamilton, Scientific Reports (vol 5, article 12948 (2015)). See http://dx.doi.org/10.1038/srep12948
8 Aug 2015
Karina Hudson and Oleh Klochan are off to Europe, to visit our collaborators at the University of Cambridge. Karina will be spending six weeks in Cambridge, developing new techniques for fabricating p-type nanostructure devices. Hopefully the English will be too restrained to mention Australia's recent world record performance in the Ashes.
5 Aug 2015
Welcome to Shota Shirai, from Tohoku University in Japan, who is doing a Practicum on Nuclear spin coupling in the QED group.
3 Aug 2015
Welcome to new PhD student Matthew Rendell.
27 Jul 2015
Alex, Ashwin, LaReine and Oleh are presenting work at the International Conference on the Electronic Properties of Two Dimensional Systems (EP2DS) in Sendai, Japan. LaReine has a talk (congrats) on her work on non-collinear spin polarisation, while Oleh is presenting his work on nuclear spin effects, and Ashwin is presenting studies of unusual spin properties of 1D hole systems.
2 Jul 2015
Welcome to Yizhou Sun, from USTC (China), who is doing a 3 month Practicum in the QED group with Dr. Oleh Klochan.
22 June 2015
Welcome to Prof. Roland Winkler (author of the book on spin-orbit interactions in semiconductors) and Prof Ulrich Zuelicke, who are visiting again to work with QED and Dimi Culcer on more hole-some fun.
9 June 2015
A step towards resolving the riddle of the "0.7 anomaly" in quantum point contacts. A new paper with our collaborators in Cambridge reports an amazingly comprehensive experimental study of 100 quantum point contacts, and finds that the behaviour of the anomalous conductance feature at 0.7x2e^2/h is consistent with the theory developed at by Oleg Sushkov's group at UNSW and Jan von Delft's group at LMU in Munich. For more details see Luke Smith L. W. Smith, H. Al-Taie, A. A. J. Lesage, F. Sfigakis, P. See, J. P. Griffiths, H. E. Beere, G. A. C. Jones, D. A. Ritchie, A. R. Hamilton, M. J. Kelly, and C. G. Smith, Dependence of the 0.7 anomaly on the curvature of the potential barrier in quantum wires, Physical Review B 91, 235402 (2015). http://dx.doi.org/10.1103/PhysRevB.91.235402.
6 May 2015
Well done to Jason Chen (QED alumnus) and Oleh Klochan - their paper on quantum point contacts that can be switched from electrons to hole conduction just by changing the gate bias has been published: J.C.H. Chen, O. Klochan, A.P. Micolich, K. Das Gupta, F. Sfigakis, D.A. Ritchie, K. Trunov, D. Reuter, A.D. Wieck, and A.R. Hamilton, Fabrication and characterisation of Gallium Arsenide ambipolar quantum point contacts, Applied Physics Letters 106, 183504 (2015). http://dx.doi.org/10.1063/1.4918934
27 Apr 2015
Congratulations to Karina Hudson, who has won an ARCNN Overseas Travel Fellowship to go to the UK and work with our collaborators at the University of Cambridge.
13 Apr 2015
Golrokh Akhgar, from Chris Pakes' group in LaTrobe, is visiting the QED group for 2 weeks to perform low temperature experiments.
19 Mar 2015
Professor David Ritchie, head of the Semiconductor Physics group at the University of Cambridge, is visiting the QED group for 3 weeks.
20 Feb 2015
Well done to Dr. Oleh Klochan - his study of the absence of coupling between hole and nuclear spins has been accepted for publication in the New Journal of Physics: O. Klochan, A.R. Hamilton, K. das Gupta, F. Sfigakis, H.E. Beere, and D.A. Ritchie, Landau level spin diode in a GaAs two dimensional hole system. A preprint is available at http://arxiv.org/abs/1406.3883
29 Jan 2015
Congratulations to Dr. Andrew See - his work in collaboration with A/Prof. Adam Micolich of the Nanoelectronics group, on controllably switching and resetting the disorder configuration in nanoscale devices has just been accepted for publication in Physical Review B. A preprint is available here: http://arxiv.org/abs/1408.4845
27 Jan 2015
Welcome to new PhD student Scott Liles.

Topic revision: r52 - 19 Apr 2017, AlexHamilton