Dr Ashton Bradley
Rutherford Discovery Fellow and Senior Research Fellow
- Room: 416
- Phone: (03) 479 4121
- Email: abradley [at] physics.otago.ac.nz
- Group website
- Researcher ID
Current Teaching
Expertise and Research Interests
I am primarily interested in ultra-cold matter waves. Since the discovery of dilute gas Bose-Einstein condensation in 1995, the physics of nano-Kelvin matter waves has been a fascinating field of scientific exploration. The field is characterized by mesoscopic quantum systems with an unrivaled level of characterization and control, thus enabling rigorous tests of theoretical concepts and clean analog realizations of phenomena that are difficult to study in other settings. Fundamental advances have been achieved in many areas, from analog models of relativistic phenomena such as the Hawking Effect, to our basic understanding of Superfluidity, to tests of the Kibble-Zurek theory of symmetry breaking in non-equilibrium phase transitions.
My current interests focus on vortex dynamics in two dimensional superfluid flows which have the advantage that the dynamics of quantum vortices is reduced to motion on a plane. I am interested in
- Superfluid turbulence
- Dynamics and statistical mechanics of vortices
I am also working on
- The stochastic Gross-Pitaevskii theory of finite temperature BECs
- Dissipative dynamics of nonlinear excitations such as vortices and solitons
Current student supervision
PhD
- Sam Rooney
Hons
- Matt Reeves
Media
Observing the dance of a vortex-antivortex pair, step by step, Physics Viewpoints
Condensed-matter physics -surviving the transition, Nature News and Views
Quantum whirlpools, Our Changing World, National Radio
Teleportation, but not as we know it, New Scientist
Selected Publications
- Quantum tunneling of a vortex between two pinning potentials, O. Fialko, A. S. Bradley, J. Brand, Physical Review Letters 108, 015301 (2012)
- Suppression of Kelvon-induced decay of quantized vortices in oblate Bose-Einstein condensates, S. J. Rooney, P. B. Blakie, B. P. Anderson, and A. S. Bradley, Physical Review A 84, 023637 (2011)
- Observation of vortex dipoles in an oblate Bose-Einstein condensate, T. W. Neely, E. C. Samson, A. S. Bradley, M. J. Davis, and B. P. Anderson, Physical Review Letters 104, 160401 (2010)
- Decay of a quantum vortex: Test of nonequilibrium theories for warm Bose-Einstein condensates, S. J. Rooney, A. S. Bradley, and P. B. Blakie, Physical Review A 81, 023630 (2010)
- Nonequilibrium dynamics of vortex arrest in a finite-temperature Bose-Einstein condensate, T. M. Wright, A. S. Bradley, R. J. Ballagh, Physical Review A 81, 013610 (2010)
- Scale-invariant thermodynamics of a toroidally trapped Bose gas, A. S. Bradley, Physical Review A 79, 033624 (2009)
- Spontaneous vortices in the formation of Bose-Einstein condensates, C. N. Weiler, T. W. Neely, D. R. Scherer, A. S. Bradley, M. J. Davis, and B. P. Anderson, Nature 455, 948 (2008)
- Dynamics and statistical mechanics of ultra-cold Bose gases using c-field techniques, P. B. Blakie, A. S. Bradley, M. J. Davis, R. J. Ballagh, and C. W. Gardiner, Advances in Physics 57, 363 (2008)
- Bose-Einstein condensation from a rotating thermal cloud: Vortex nucleation and lattice formation, A. S. Bradley, C. W. Gardiner, and M. J. Davis, Physical Review A 77, 033616 (2008)
- Raman scheme to measure the quantum statistics of an atom laser beam, A. S. Bradley, M. K. Olsen, S. A. Haine, and J. J. Hope, Physical Review A 76, 033603 (2007)
- Bright tripartite entanglement in triply concurrent parameteric oscillation, A. S. Bradley, M. K. Olsen, O. Pfister, and R. C. Pooser, Physical Review A 72, 053805 (2005)
- Properties of the stochastic Gross-Pitaevskii equation: Projected Ehrenfest relations and the optimal plane wave basis, A. S. Bradley, P. B. Blakie, and C. W. Gardiner, Journal of Physics B 38, 4259 (2005)