Speaker: Dr Tyler Neely
Affiliation: University of Queensland


The point vortex approximation for two-dimensional fluid flows describes “vortex matter”, where the constituent particles are the locally swirling elements of the fluid – point vortices. These systems exhibit complex dynamics, owing to long-range interactions and bounded phase spaces, leading to exotic high-energy equilibrium states that can be described by absolute negative Boltzmann temperatures.

Similar to normal matter, chiral vortex matter, consisting of point vortices all with the same sign of circulation, can exhibit solid, liquid, and gas “phases”. While the solid and liquid phases describe a range of phenomena in quantum fluids, such as high-temperature superconductivity, the fractional quantum Hall effect, and rotational glitches in neutron stars, the gas phase has remained experimentally elusive, as it is strongly affected by energy loss.

I will describe our ongoing experiments on the gas phase of chiral vortex matter. By using a uniform disc-shaped Bose-Einstein condensate, we experimentally realise a system of point vortices isolated from the external environment, and we have precise experimental control of the initial energy and angular momentum of the vortices. By initialising the vortices in highly non-equilibrium configurations, we demonstrate thermalisation on experimental timescales. The vortex distributions realised are in excellent agreement with the predictions of the microcanonical ensemble.

About Australia - New Zealand Cold Atom Seminars

This new initiative hosts a seminar once a month for the Australia – New Zealand cold atom research community.  The purpose is to encourage and facilitate ongoing discussions and collaboration in the local community.  Talks should be less than 40 minutes in length to allow ample time for questions and discussion.

Seminars will be held on the last Friday of the month (except for December) at 1pm Melbourne time (which is normally 3pm New Zealand time).  While the primary format is online via Zoom, various institutions will host the seminar in local seminar rooms.  The Zoom link is https://uqz.zoom.us/j/88604569495

You can sign up for announcements for the seminars at this webpage:

Seminars are recorded, and past seminars can be accessed from this web page.

Contact Matthew Davis mdavis@physics.uq.edu.au for further information.



Physics Annexe (06)
407 (or via Zoom address https://uqz.zoom.us/j/88604569495)