Annual Report 2009.pdf - School of Physics - University of Melbourne

group reports& publicationstheoretical condensed matter physics(TCMP)A/Prof Les AllenHighlights from the Centre for Quantum ComputingTechnology (CQCT) theory program led by ProfessorLloyd Hollenberg include:• a concept paper on decoherence based detection(Nanotechnology),• a proposal for mapping donor electron wavefunctions in silicon using 29Si spin probes(Physical Review Letters), with the Purduegroup,• a follow up on the theory for decoherencedetection sensitivity for randomly fluctuatingmagnetic fields (Physical Review Letters) byPhD student Liam Hall.• The use of NV diamond for a novel detection ofthe Aharonov-Casher phase was carried out byPhD student Dougal Maclaurin in collaborationwith Dr. Andy Martin and Dr. Andy Greentree(Physical Review A, Rapid Communication).• CQCT postdocs A. Fowler and C. Hill completedwork in surface code based quantumcommunication protocols and multiple receiverquantum transport protocols respectively.• The group also participated in the first singleelectron spin readout in silicon achieved at theUNSW node of the CQCT.QE II Fellow Dr Andy Greentree and his studentscontinued investigating single photon nonlinearoptics and the Jaynes-Cummings-Hubbard model(solid-light). Outputs from the year included• an invited book chapter (with Prof. Hollenberg),16 published journal articles, and, with Prof.Steven Prawer,• two ARC grants relating to quantum optics indiamond were obtained. The first grant is aDiscovery Project that will bring Dr Tomljenovic-Hanic to the TCMP group in 2010 as a newAustralian Research Fellow. The second isa linkage project with Hewlett-Packard. DrGreentree maintains active collaborationswith NII Tokyo, HP Bristol and HP Palo Alto,TU Karlsruhe, UNSW and the University ofAdelaide.collaborations (UK, the Netherlands, Canada, NewZealand, Japan and Germany). Highlights of thiswork include• a proposal to measure large topologicalAharonov-Casher phases in nitrogen vacancycenters in diamond and presented a newtechnique to study the fundamental propertiesof ultracold dipolar gases. As a result of thiswork Dr. Andy Martin gave an invited talk at theUniversity of Otago, New Zealand.The highlight for the subgroup of Professor LesAllen, working mainly on imaging beyond thenanoscale, was a paper published with the groupof Professor Susanne Stemmer from the Universityof California in Santa Barbara in which quantitativebright field imaging in scanning transmissionelectron microscopy was described for the firsttime. These results are related to imaging in aconventional transmission electron microscope bythe quantum mechanical principle of reciprocity andthus make direct comment on the long standingand important problem of lack of contrast (typically200 - 500%) typically found in that mode of imaging(the so-called Stobbs factor). Our results show thatit is not the theory of how fast electrons interactwith condensed matter which is at the root of thecontrast problem, as has been widely speculated.Papers were also published on quantitativeZ-contrast imaging of crystals containing heavyelements, a model of phonon excitation by fastelectrons in a crystal with correlated atomic motionsand a paper incorporating the theory of multiplescattering of the probe electron in electron energylossspectroscopy. Professor Allen delivered invitedkeynote contributions at international conferences inCanada, the UK and Taiwan.Dr Andy Martin, Senior Lecturer in the TCMP Group,published 7 papers (including two in A* ERA rankedjournals) in the fields of ultracold dilute gas dynamicsand topological phase measurements using defectsin diamond. This work involved several international44www.physics.unimelb.edu.au