Mesoscopic cold atom systems in and out of equilibrium

Workshop Report

This mpipks workshop was held during the period September 7-11, 2020 and was originally planned as a “regular” in person workshop with about 80 participants. Given the Covid-19 situation worldwide, the scientific organizers decided in May 2020, after a number of informative discussions with the mpipks staff (Mandy Lochar and Dr. Michael Genkin), to change the workshop format to a fully virtual workshop via the Zoom platform. To accommodate the different time zones, the invited talks were shortened to 30 minutes and distributed among three morning sessions (“Europe and Asia friendly time”) and three afternoon sessions (“Europe and North/South America friendly time”). In order to maintain the character of a workshop and to foster scientific discussion, the invited talks were complemented by two discussion sessions, which were organized around a few selected topics in separate Zoom sessions. Due to the online nature of the workshop, the poster session had, unfortunately, to be canceled. All invited speakers gave their consent for the talks to be recorded and to be available for registered participants via a password protected website hosted by the mpipks for 48-hour viewing.
The workshop registration was closed just a few days prior to the start of the workshop and 157 participants from 22 countries were accepted. The talks were attended by a “live" audience of between 35 and 85 participants and the individual discussion rooms drew up to 10 people each. The Max-Planck colloquium, which was given by MacArthur fellow Ana-Maria Rey, drew an audience close to 150. The recordings of the individual talks were accessed between 457 and 1250 times. Speaker invitations went out between 12 to 18 months ahead of the workshop; most individuals approached accepted the invitation right away. Even after the switch from the in-person to the virtual format only one invited speaker canceled their participation. The demographics of the invited speakers was diverse in many aspects: 14 were located in Europe, 5 in the US, and 1 each in China and Australia. Seven of the speakers were female and 14 were male. The career stage of the speakers ranged from postdoctoral researcher (Bienias and Williams) to group leader (Luitz) to senior researcher/faculty. Two of the speakers (Greiner and Rey) are MacArthur fellows.
The key topics and questions addressed during the workshop covered many aspects that are currently driving the field of medium sized cold atomic systems from experimental and theoretical points of view. These included how to observe non-classical correlations between constituents such as atoms, molecules, quasi-particles or spins of mesoscopic systems, and how to apply them; how possible deviations from the eigenstate thermalisation hypothesis can be observed and studied in mesoscopic systems; how transitions between coherent and incoherent quantum diffusion can be observed; how non-equilibrium descriptions can be effectively benchmarked, theoretically and experimentally, and what the limits of non-adiabatic evolution are. On a more sad note, Bruno Julia-Diaz gave an in-memoriam presentation about Artur Polls, who was a highly valued member of the community and had passed away unexpectedly just before the workshop in August 2020. Despite this new and unfamiliar workshop format, the feedback received from the speakers and participants confirmed the need for workshops of this kind in times where face-to-face exchanges across borders are not possible.
We would like to sincerely thank the mpipks for supporting this event in its online form. We are particularly grateful to Mandy Lochar and Dr. Michael Genkin who were invaluable in helping us to work out the organizational details and ensured a smooth running of the workshop.