212 citations · 479 across the 13 of their papers we have counts for
13 papers
Extracting work from coherence in a two-mode Bose-Einstein condensate
L. A. Williamson, F. Cerisola, J. Anders +1
We show how work can be extracted from number-state coherence in a two-mode Bose-Einstein condensate. With careful tuning of parameters, a sequence of thermodynamically reversible…
Berezinskii-Kosterlitz-Thouless transitions in a ferromagnetic superfluid: effects of axial magnetization
Andrew P. C. Underwood, Andrew J. Groszek, Xiaoquan Yu +2
An easy-plane ferromagnetic spin-1 Bose gas undergoes two Berezinskii-Kosterlitz-Thouless (BKT) transitions, associated with mass and spin superfluidity respectively. We study the…
Dynamics of Polar-Core Spin Vortices in Inhomogeneous Spin-1 Bose-Einstein Condensates
Zachary L. Stevens-Hough, Matthew J. Davis, Lewis A. Williamson
In the easy-plane phase, a ferromagnetic spin-1 Bose-Einstein condensate is magnetized in a plane transverse to the applied Zeeman field. This phase supports polar-core spin vortic…
Many-body enhancement in a spin-chain quantum heat engine
L. A. Williamson, Matthew J. Davis
We show that ferromagnetic interactions can enhance the adiabatic performance of a quantum spin chain engine at low temperatures. The enhancement in work output is particular prono…
A damped point-vortex model for polar-core spin vortices in a ferromagnetic spin-1 Bose-Einstein condensate
Lewis A. Williamson, P. B. Blakie
Ferromagnetic spin-1 Bose-Einstein condensates in the broken-axisymmetric phase support polar-core spin vortices (PCVs), which are intimately linked to the nonequilibrium dynamics…
Optical response of atom chains beyond the limit of low light intensity: The validity of the linear classical oscillator model
L. A. Williamson, J. Ruostekoski
Atoms subject to weak coherent incident light can be treated as coupled classical linear oscillators, supporting subradiant and superradiant collective excitation eigenmodes. We id…
Anomalous phase ordering of a quenched ferromagnetic superfluid
L. A. Williamson, P. B. Blakie
Coarsening dynamics, the canonical theory of phase ordering following a quench across a symmetry breaking phase transition, is thought to be driven by the annihilation of topologic…
Coarsening dynamics of an isotropic ferromagnetic superfluid
Lewis A. Williamson, P. B. Blakie
In zero magnetic field the ground state manifold of a ferromagnetic spin-1 condensate is SO(3) and exhibits vortices as topological defects. We investigate the phase…
Dynamics of polar-core spin vortices in a ferromagnetic spin-1 Bose-Einstein condensate
Lewis A. Williamson, P. B. Blakie
A ferromagnetic spin-1 condensate supports polar-core spin vortices (PCVs) in the easy-plane phase. We derive a model for the dynamics of these PCVs using a variational Lagrangian…
Coarsening and thermalisation properties of a quenched ferromagnetic spin-1 condensate
Lewis A. Williamson, P. B. Blakie
We examine the dynamics of a quasi-two-dimensional spin-1 condensate in which the quadratic Zeeman energy q is suddenly quenched to a value where the system has a ferromagnetic gro…
Universal coarsening dynamics of a quenched ferromagnetic spin-1 condensate
Lewis A. Williamson, P. B. Blakie
We demonstrate that a quasi-two-dimensional spin-1 condensate quenched to a ferromagnetic phase undergoes universal coarsening in its late time dynamics. The quench can be implemen…
Cavity enhanced rephased amplified spontaneous emission
Lewis A Williamson, Jevon J Longdell
Amplified spontaneous emission is usually treated as an incoherent noise process. Recent theoretical and experimental work using rephasing optical pulses has shown that rephased am…
A magneto-optic modulator with unit quantum effciency
Lewis A. Williamson, Yu-Hui Chen, Jevon J. Longdell
We propose a device for the reversible and quiet conversion of microwave photons to optical sideband photons, that can reach 100% quantum effciency. The device is based on an erbiu…