Winter School on Strongly Correlated Quantum Matter

The virtual “Winter School on Strongly Correlated Quantum Matter”, organized jointly with
ICTP Trieste, took place from 30 November to 18 December 2020. The Covid19 pandemic has
drastically affected scientific exchange. On a seminar and colloquium level many virtual activities
have been successfully started around the globe to compensate for the lack of real meetings and
events. However, a substantial gap has remained when it comes to activities targeted at Master
and PhD students as well as other junior researchers. This has been the key motivation for us to
initiate the virtual Winter School with the purpose to provide a modern overview of the field of
strongly correlated quantum matter and to provide a platform for reinforcing scientific exchange
during the present times characterized by severe travel constraints.

The winter school extended over three weeks. As the typical attention span in virtual formats is
limited as compared to formats in presence we designed the scientific program in a very dilute form.
For that purpose, we have been targeting at most 3 lecture, tutorial, or colloquium events a day and
also left 2 days free for self studies. Overall, we were hosting 8 lectures with accompanying
tutorials, 3 colloquia, and 3 poster sessions.

The lectures and colloquia were held by leading scientists performing cutting-edge research in the
respective fields, while the tutorials were given by junior collaborators. Overall, we have admitted
roughly 150 external participants. We have observed live attendance of around 90 in the first week,
80 in the second week, and 60 in the third week. Importantly, however, we have also recorded and
made available the events online for download. From a subsequent survey we have learned that
almost 50 % of the participants were also watching the recordings at a later stage, which let’s us
speculate that overall a large fraction of participants were attending the school.

In order to be as inclusive as possible, we decided to use BigBlueButton (BBB) as our video
conferencing platform. BBB is open source software and was hosted on a dedicated server at MPIPKS,
after initial attempts with a virtual machine were unsuccessful. For users, BBB is web browser
based and easy to use, although operation is not as smooth as with fine tuned proprietary software
like zoom. After instructing participants to use recent chromium based browsers and to open only
one connection, BBB ran relatively smoothly. We had minor problems with some speakers who had
a weak internet connection, in which case we used zoom as a fallback option.

It appears that most technical problems with BBB are manageable, and the fact that it is open
source makes it preferable over zoom.

In parallel to the video sessions, we established an independent, asynchronous communication
channel among all participants, based on the open source Matrix platform. We created one chat
room per lecture and encouraged participants to ask questions and discuss among themselves on
Matrix instead of the builtin BBB chat. There are two advantages with that: The Matrix chat is
persistent even after the end of the school and in case of technical problems with BBB, Matrix was
still operational, allowing to solve problems in real time. The discussion on Matrix was generally
lively and several initiatives from the participants emerged, such as collaborative writing of lecture
notes for some lectures. This helped generating a feeling of a school community, which is very
difficult to create in remote events. According to the subsequent survey roughly 25% of the
participants utilized matrix for their own interactions, beyond the official channels we had
established.