Welcome to the web page of the Quantum Electronic Devices group in UNSW's School of Physics
QED group December 2012 (Photo: Mike Gal) |
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.
- 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.
- 19 Dec 2014
- Congratulations to Sarah and Andrew - their paper reporting a new hybrid architecture for making shallow accumulation mode AlGaAs/GaAs heterostructure devices has just been accepted for publication in Applied Physics Letters.
- 10 Dec 2014
- Alex Hamilton elected as a Fellow of the American Physical Society "for contributions to the understanding of quantum confined holes in low dimensional semiconductor structures". This wouldn't have been possible without the hard work of all members of the group - thank you, and the next round of drinks is on Alex!
- 8 Dec 2014
- Another paper in Nano Letters! Well done to Mark Edmonds and Oleh Klochan; their paper reporting direct evidence of the two dimensional nature of the surface conducting layer in hydrogen terminated diamond, with the observation of weak antilocalisation, has just been published in Nano Letters: Spin–Orbit Interaction in a Two-Dimensional Hole Gas at the Surface of Hydrogenated Diamond, Mark T. Edmonds, Laurens H. Willems van Beveren, Oleh Klochan, Jiri Cervenka, Kumar Ganesan, Steven Prawer, Lothar Ley, Alexander R. Hamilton, and Christopher I. Pakes, http://pubs.acs.org/doi/abs/10.1021/nl502081y.
- 3 Dec 2014
- Congratulations to LaReine Yeoh. Ashwin Srinivasan and Oleh Klochan! Their paper on the strange magnetic properties of quantum confined holes, showing that a magnetic field applied in one direction can generate a spin polarisation at right angles to the applied magnetic field, has been published in Physical Review Letters: L.A. Yeoh, A. Srinivasan, O. Klochan, R. Winkler, U. Zülicke, M.Y. Simmons, D.A. Ritchie, M. Pepper, and A.R. Hamilton, Noncollinear Paramagnetism of a GaAs Two-Dimensional Hole System, Phys. Rev. Lett. 113, 236401 (2014).
- 10 Nov 2014
- Congratulations to Dr Ashwin Srinivasan on the award of his PhD, with outstanding referee reports.
- 5 Nov 2014
- Alex and Dimi Culcer are awarded a $613,000 ARC Discovery Grant to investigate the properties of hole quantum dots.
- 28 July 2014
- Shun-Tsung Lo, who visited us last year, has had his paper on " Transport in disordered monolayer MoS2 nanoflakes—evidence for inhomogeneous charge transport published in Nanotechnology 25, 375201 (2014). Well done to Shun-Tsung, Oleh Klochan, and all the authors.
- 9 February 2014
- Another theory paper, in collaboration with colleagues in Italy, has appeared in Physical Review B Rapid Communications: Excitonic superfluidity and screening in electron-hole bilayer systems, by Perali, Neilson and Hamilton. The calculations show that electron-hole superfluidity can be achieved in double bilayer graphene devices, and answers a longstanding question about the suppression of superfluid pairing by screening (and vice versa).
- 10 February 2014
- Welcome to new Honours student Scott Liles.
- 7 February 2014
- Congratulations to Ashwin Srinivasan for winning a best poster prize at the 2014 Wagga Wagga meeting in Waiheke Island.
- 4 February 2014
- Alex, Ashwin and LaReine are off to Waiheke island in New Zealand for the 2014 Wagga Wagga meeting, where LaReine is going to talk about her recent work on quantum dots.
- 3 February 2014
- Oleh is off to Adelaide for the 2014 ICONN conference, where he is giving a talk on Hole Landau Level Spin Diodes.
- 7 January 2014
- Congratulations to Sarah, Andrew, Zach and Pat - their paper showing that high frequency measurements of undoped quantum dots are possible, despite what lumped circuit models predict, has just appeared in Applid Physics Letters:
S. J.!MacLeod, A. M. See, Z. K. Keane, P. Scriven, A. P. Micolich, M. Aagesen, P. E. Lindelof and A. R. Hamilton, Radio-frequency reflectometry on an undoped AlGaAs/GaAs single electron transistor, Appl. Phys. Lett. 104, 012114 (2014). It's also available on the arxiv preprint server.