Welcome
I am an associate professor of physics at the University of Otago, New Zealand. My group’s work spans multiple disciplines of theoretical and mathematical physics, including condensed matter, degenerate gases, hydrodynamics, atomic physics, quantum optics and quantum information.
Interests
- Condensed matter
- Degenerate Gases
- Hydrodynamics
- Atomic Physics
- Quantum Optics
- Quantum Information
- Quantum Turbulence
- Open Quantum Systems
Research Interests
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Publications
Quickly discover relevant content by filtering publications.
(2022).
Turbulent Relaxation to Equilibrium in a Two-Dimensional Quantum Vortex Gas.
Physical Review X.
(2021).
Scaling Dynamics of the Ultra-Cold Bose Gas.
arXiv:2112.09280 [cond-mat, physics:physics, physics:quant-ph].
(2021).
Spectral Analysis for Compressible Quantum Fluids.
arXiv:2112.04012 [cond-mat, physics:math-ph, physics:quant-ph].
(2021).
Spin-Orbit- and Coherently-Coupled Spin-1 Bose-Einstein Condensates under Rotation.
arXiv:2110.02185 [cond-mat].
(2021).
Superflow Decay in a Toroidal Bose Gas: The Effect of Quantum and Thermal Fluctuations.
SciPost Physics.
(2021).
Steady States, Squeezing, and Entanglement in Intracavity Triplet down Conversion.
Optics Communications.
(2021).
Neutral Vortex Necklace in a Trapped Planar Superfluid.
Journal of Low Temperature Physics.
(2020).
Dynamics of Hot Bose-Einstein Condensates: Stochastic Ehrenfest Relations for Number and Energy Damping.
SciPost Physics.
(2019).
Thermally Robust Spin Correlations between Two 85 Rb Atoms in an Optical Microtrap.
Nature Communications.
(2019).
Snell's Law for a Vortex Dipole in a Bose-Einstein Condensate.
SciPost Physics.
(2019).
Giant Vortex Clusters in a Two-Dimensional Quantum Fluid.
Science.
(2018).
Mesoscopic Dynamical Differences from Quantum State Preparation in a Bose-Hubbard Trimer.
Physical Review Letters.
(2017).
Emergent Non-Eulerian Hydrodynamics of Quantum Vortices in Two Dimensions.
Physical Review Letters.
(2017).
Enstrophy Cascade in Decaying Two-Dimensional Quantum Turbulence.
Physical Review Letters.
(2017).
Quantum-Correlated Twin-Atom Laser from a Bose-Hubbard System.
Physical Review A.
(2016).
Theory of the Vortex-Clustering Transition in a Confined Two-Dimensional Quantum Fluid.
Physical Review A.
(2016).
Brownian Motion of a Matter-Wave Bright Soliton Moving through a Thermal Cloud of Distinct Atoms.
Physical Review A.
(2016).
Reservoir Interactions of a Vortex in a Trapped Three-Dimensional Bose-Einstein Condensate.
Physical Review A.
(2015).
Low-Dimensional Stochastic Projected Gross-Pitaevskii Equation.
Physical Review A.
(2015).
Reservoir Interactions during Bose-Einstein Condensation: Modified Critical Scaling in the Kibble-Zurek Mechanism of Defect Formation.
Physical Review A.
(2015).
Coherence and Linewidth of a Continuously Pumped Atom Laser at Finite Temperature.
Physical Review A.
(2015).
Identifying a Superfluid Reynolds Number via Dynamical Similarity.
Physical Review Letters.
(2015).
Quantum Ultracold Atomtronics.
Physical Review A.
(2015).
Oscillons in Coupled Bose-Einstein Condensates.
Physical Review A.
(2015).
Spectral Energy Transport in Two-Dimensional Quantum Vortex Dynamics.
Physical Review A.
(2014).
Stochastic Projected Gross-Pitaevskii Equation for Spinor and Multicomponent Condensates.
Physical Review A.
(2014).
Dynamic and Energetic Stabilization of Persistent Currents in Bose-Einstein Condensates.
Physical Review A.
(2014).
Onsager-Kraichnan Condensation in Decaying Two-Dimensional Quantum Turbulence.
Physical Review Letters.
(2014).
Numerical Method for the Stochastic Projected Gross-Pitaevskii Equation.
Physical Review E.
(2014).
Signatures of Coherent Vortex Structures in a Disordered Two-Dimensional Quantum Fluid.
Physical Review A.
(2013).
Characteristics of Two-Dimensional Quantum Turbulence in a Compressible Superfluid.
Physical Review Letters.
(2013).
Persistent-Current Formation in a High-Temperature Bose-Einstein Condensate: An Experimental Test for Classical-Field Theory.
Physical Review A.
(2013).
Kibble-Zurek Scaling and Its Breakdown for Spontaneous Generation of Josephson Vortices in Bose-Einstein Condensates.
Physical Review Letters.
(2013).
Inverse Energy Cascade in Forced Two-Dimensional Quantum Turbulence.
Physical Review Letters.
(2012).
Classical and Quantum Regimes of Two-Dimensional Turbulence in Trapped Bose-Einstein Condensates.
Physical Review A.
(2012).
Stochastic Projected Gross-Pitaevskii Equation.
Physical Review A.
(2012).
Energy Spectra of Vortex Distributions in Two-Dimensional Quantum Turbulence.
Physical Review X.
(2012).
Quantum Tunneling of a Vortex between Two Pinning Potentials.
Physical Review Letters.
(2011).
Suppression of Kelvon-Induced Decay of Quantized Vortices in Oblate Bose-Einstein Condensates.
Physical Review A.
(2010).
Analysis of a Continuous-Variable Quadripartite Cluster State from a Single Optical Parametric Oscillator.
Physical Review A.
(2010).
Geometric Scale Invariance as a Route to Macroscopic Degeneracy: Loading a Toroidal Trap with a Bose or Fermi Gas.
Physical Review A.
(2010).
Observation of Vortex Dipoles in an Oblate Bose-Einstein Condensate.
Physical Review Letters.
(2010).
Decay of a Quantum Vortex: Test of Nonequilibrium Theories for Warm Bose-Einstein Condensates.
Physical Review A.
(2010).
Nonequilibrium Dynamics of Vortex Arrest in a Finite-Temperature Bose-Einstein Condensate.
Physical Review A.
(2010).
Quadripartite Continuous-Variable Entanglement via Quadruply Concurrent down-Conversion.
Physical Review A.
(2009).
Finite-Temperature Dynamics of a Single Vortex in a Bose-Einstein Condensate: Equilibrium Precession and Rotational Symmetry Breaking.
Physical Review A.
(2009).
Numerical Representation of Quantum States in the Positive-P and Wigner Representations.
Optics Communications.
(2009).
Numerical Method for Evolving the Dipolar Projected Gross-Pitaevskii Equation.
Physical Review E.
(2009).
Scale-Invariant Thermodynamics of a Toroidally Trapped Bose Gas.
Physical Review A.
(2008).
Dynamical Thermalization and Vortex Formation in Stirred Two-Dimensional Bose-Einstein Condensates.
Physical Review A.
(2008).
Spontaneous Vortices in the Formation of Bose–Einstein Condensates.
Nature.
(2008).
Dynamics and Statistical Mechanics of Ultra-Cold Bose Gases Using c-Field Techniques.
Advances in Physics.
(2008).
Bose-Einstein Condensation from a Rotating Thermal Cloud: Vortex Nucleation and Lattice Formation.
Physical Review A.
(2008).
Bright Bichromatic Entanglement and Quantum Dynamics of Sum Frequency Generation.
Physical Review A.
(2008).
From Squeezed Atom Lasers to Teleportation of Massive Particles.
European Physical Journal-Special Topics.
(2007).
Tripartite Entanglement and Threshold Properties of Coupled Intracavity Down-Conversion and Sum-Frequency Generation.
Physical Review A.
(2007).
Raman Scheme to Measure the Quantum Statistics of an Atom Laser Beam.
Physical Review A.
(2007).
Continuous Variable Tripartite Entanglement and Einstein-Podolsky-Rosen Correlations from Triple Nonlinearities.
Optics and Spectroscopy.
(2007).
Quantum de Laval Nozzle: Stability and Quantum Dynamics of Sonic Horizons in a Toroidally Trapped Bose Gas Containing a Superflow.
Physical Review A.
(2007).
Quantum Statistical Measurements of an Atom Laser Beam.
Nuclear Physics A.
(2007).
Quantum Depletion of Collapsing Bose-Einstein Condensates.
Physical Review A.
(2006).
Asymmetric Polychromatic Tripartite Entanglement from Interlinked χ(2)Parametric Interactions.
Physical Review A.
(2006).
Continuous Variable Tripartite Entanglement and Einstein–Podolsky–Rosen Correlations from Triple Nonlinearities.
Journal of Physics B: Atomic, Molecular and Optical Physics.
(2006).
Three-Body Recombination of Ultracold Bose Gases Using the Truncated Wigner Method.
Physical Review A.
(2005).
Continuous Variable Tripartite Entanglement from Twin Nonlinearities.
Journal of Physics B: Atomic, Molecular and Optical Physics.
(2005).
Bright Tripartite Entanglement in Triply Concurrent Parametric Oscillation.
Physical Review A.
(2005).
Properties of the Stochastic Gross–Pitaevskii Equation: Finite Temperature Ehrenfest Relations and the Optimal Plane Wave Representation.
Journal of Physics B: Atomic, Molecular and Optical Physics.
(2005).
Phase-Space Analysis of Bosonic Spontaneous Emission.
Optics Communications.
(2004).
Fock-State Dynamics in Raman Photoassociation of Bose-Einstein Condensates.
Physical Review A.
(2003).
Steady-State Quantum Statistics of a Non-Markovian Atom Laser. II.
Physical Review A.
(2002).
Theory of Ramsey Spectroscopy and Anomalous Segregation in Ultracold Rubidium.
Journal of Physics B: Atomic, Molecular and Optical Physics.
(2001).
Theory of the Cold Collision Frequency Shift in 1S-2S Spectroscopy of Bose-Einstein-Condensed and Non-Condensed Hydrogen.
Journal of Physics B: Atomic, Molecular and Optical Physics.
(2001).
Analysis of g(2) for the Cold Collision Frequency Shift in the Hydrogen Condensate Experiments.
Journal of Physics B: Atomic, Molecular and Optical Physics.
People
Current students
- Tommy Fischer (Hons 2022)
- Tim Copland (Summer)
- Erix Xu (MSc)
- Zain Mehdi (PhD ANU; primary advisor Stuart Szigeti)
Research fellows and postdocs
- R. Kishor Kumar RF 2020-present
- Sukla Pal, PD 2019-2021
- Xiaoquan Yu, RF 2015-2019
- Thomas Billam, PD 2014-2016
Current collaborators
- Prof Brian Anderson, University of Arizona
- Dr Tyler Neely, University of Queensland
- Dr Matthew Reeves, University of Queensland
- Prof Matthew Davis, University of Queensland
- Dr Stuart Szigeti, Australian National University
- Prof David Snoke, University of Pittsburgh
- Dr Shouvik Mukherjee, University of Maryland, College Park
Graduates
- Jordan Clarke (MSc 2022)
- Michael Cawte (MSc 2019)
- Rob McDonald (PhD 2019)
- Mathew Denys (Hons 2018)
- Peter Barnett (Hons 2017)
- Matthew Reeves (PhD 2017)
- Zaki Atayee (Hons 2015)
- Tom Blennerhassett (Hons 2015)
- Sam Rooney (PhD 2015)
- Malcolm Morrison (Hons 2013)
- Kyle Wright (Hons 2010)
Externally Funded Visiting Researchers
- Murray Olsen, Quantum Science Otago and Dodd-Walls Fellow 2017-2018
- Stuart Szigeti, Australian Research Council Endeavour Fellowship 2017
- Jinyan Li, Chinese Scholarship Council Fellow 2017
- Chao-Fei Liu, Chinese Scholarship Council Fellow 2015
Theses Supervised
BSc (Hons)
- Eric Xu (Otago 2019), Scattering of Bogoliubov waves by a quantum vortex dipole
- Mathew Denys (Otago 2018), Triplet Down Conversion using Optical Phase Space Methods. Published as Mathew D. E. Denys, Murray K. Olsen, Luke S. Trainor, Harald G. L. Schwefel, and Ashton S. Bradley Optics Communications 484, 126699 (2021)
- Peter Barnett (Otago 2017), Two-Time Correlations of an Energy-Damped Bose-Einstein Condensate. Published as Rob G. McDonald, Peter S. Barnett, Fradom Atayee, Ashton S. Bradley SciPost Phys. 8, 029 (2020)
- Zaki Atayee (Otago 2016), Kohn Mode Damping in a Bose-Einstein Condensate
- Michael Cawte (Otago 2016), Vortex Dynamics and Spectra Fluctuations in a Superfluid Disk
- Tom Blennerhassett (Otago 2015) Energy Damping in Two Dimensional quantum Turbulence
- Rob McDonald (Otago 2013), Decay of Persistent Current in a Two-Dimensional Superfluid
- Malcolm Morrison (Otago 2013), A Quantum Kuramoto Model
- Matthew Reeves (Otago 2011), Two-Dimensional Quantum Turbulence in Stirred Bose-Einstein Condensates. Published as M. T. Reeves, B. P. Anderson, A. S. Bradley Physical Review A 86, 053621 (2012)
- Kyle Wright (Otago 2010), Decay of a dark soliton in a warm Bose-Einstein condensate: a variational approach
- Samuel Rooney (Otago 2009), Single Vortex Dynamics in High Temperature Bose-Einstein Condensates. Published as S. J. Rooney, A. S. Bradley, and P. B. Blakie Physical Review A 81, 023630 (2010)
Cotutelle (BSc Hons)
- Clervie Pennarun, University of Queensland 2007 (co-advisor)
Published as C. Pennarun, A. S. Bradley, and M. K. Olsen Physical Review A 76, 063812 (2007) - Florent Alzetto, University of Queensland 2006 (co-advisor).
MSc
- Eric Xu (Otago 2022)
- Jordan Clarke (Otago 2022), Expansion Dynamics of Vortices in Trapped Planar Bose-Einstein Condensates
- Michael Cawte (Otago 2019), Snell’s Law and Necklace States for Vortex Dipoles in a Quantum Gas
- Rob McDonald (Otago 2015), C-Field Theory of Dynamics in One Dimensional Bose Gases: The Kibble-Zurek Mechanism and Bright Soliton Arrest
- Matthew Reeves (Otago 2013), Inverse Energy Cascade in Two-Dimensional Quantum Turbulence
- Samuel Rooney (Otago 2011), C-field description of the quasi-equilibrium Bose gas: persistent currents and Kelvon-induced vortex decay
PhD
Primary Advisor
- Rob McDonald (Otago 2019), Anomalous Dissipation in Bose Gases: Analytic Theory of Energy Damping
- Matthew Reeves (Otago 2017), Quantum Analogues of Two-Dimensional Classical Turbulence
- Sam Rooney (Otago 2014), Implementation and Applications of the Stochastic Projected Gross-Pitaevskii Equation [Science Division Exceptional Thesis Award]
Secondary Advisor
- Chris Foster (Queensland 2011), Physics of low-dimensional ultracold Bose gases
(primary advisor Prof Matthew Davis) - Andrew Ferris (Queensland 2009), Thermalisation, correlations and entanglement in Bose-Einstein condensates
(primary advisor Prof Matthew Davis)
Teaching
Courses taught (or co-taught)
2022
- PHSI365 Computational Physics
- ELEC441 Linear Systems and Noise
- PHSI222 Electromagnetism
2021
- PHSI331 Quantum Mechanics
- PHSI365 Computational Physics
- ELEC441 Linear Systems and Noise
- PHSI222 Electromagnetism
2020
- PHSI365 Computational Physics
- ELEC441 Linear Systems and Noise
2019
- PHSI331 Quantum Mechanics
- PHSI365 Computational Physics
2018
- PHSI331 Quantum Mechanics
- PHSI365 Computational Physics
- ELEC424 Advanced Quantum Mechanics II
2017
- PHSI132 Fundamentals of Modern Physics
- PHSI365 Computational Physics
- PHSI331 Quantum Mechanics
- ELEC424 Advanced Quantum Mechanics II
2016
- PHSI365 Computational Physics
2015
- PHSI331 Quantum Mechanics
2013
- PHSI336 Mathematical Physics
2012
- PHSI334 Advanced Topics
2011
- PHSI334 Advanced Topics
2010
- PHSI334 Advanced Topics
2009
- PHSI453 Advanced Quantum Mechanics
Code
Julia code on Github
More packages will come here as we develop more julia tools for computational physics.
- VortexDistributions.jl
- PhaseSpaceTools.jl
- FourierGPE.jl
- QuantumFluidSpectra.jl
- ScalingDynamics.jl
Open source for open science!
Media
Our research in news media
- New findings on Fluid Turbulence, Ashton Bradley on Nights with Bryan Crump, Radio New Zealand 2019
- Otago–Queensland researchers observe 70-year-old prediction, with wide-reaching effects
- Order emerges from chaos in 2D vortices, Ashton Bradley in Physics Today 2019
- Quantum Entanglement at an Individual Atom Scale, Ashton Bradley work with Mikkel Anderson’s group in DWC annual report 2018
- Emergent Non-Eulerian Hydrodynamics of Quantum Vortices in Two Dimensions, Asia-Pacific Physics News Letter, p 60
- Otago Research Helping to Unlock Superfluid Mysteries, Ashton Bradley in Otago Daily Times 2015
- Rutherford Discovery Fellowship, Ashton Bradley in Otago Daily Times 2010
- Quantum Whirlpools, Ashton Bradley and Crispin Gardiner on Our Changing World with Veronika Meduna, Radio New Zealand 2008
- Vortices spontaneously arise as a Bose-Einstein condensate forms, Ashton Bradley in Physics Today 2008
- Teleportation method proposed by Australian scientists, Ashton Bradley in Physics.org 2007