On June 1-2 2017, King’s College London was host to WoLQS, a Workshop on Localisation in Quantum Systems.

This was a student-led initiative, with 9 CANES students taking different organising roles. It was aimed at early-career researchers, with each of the three invited speakers giving a two-part seminar, the first part being pedagogical and the second focusing on their recent research in different aspects of localisation in quantum systems.

Prof. Kravtsov’s (ICTP Trieste) seminar focused on extended, non-ergodic phases. He introduced Anderson localisation (AL), and explained the relevance of AL on graphs with local tree-like structure to the problem of MBL. He then defined multifractality, and illustrated how it can be used to characterise localisation and ergodicity. This set the stage for the advanced talk, in which Prof. Kravtsov presented analytical and numerical results characterising the extended non-ergodic phases of the random regular graph and related models.

 

In his introductory lecture, Dr. Z. Papić (Leeds University) discussed many-body localisation on lattices, outlining some defining characteristics. He then introduced the celebrated description of the MBL phase in terms of quasi-local effective spins, helping to shed light on the physical significance of MBL. In his second talk, Dr. Papic focussed on the entanglement spectrum, outlining how it is characterised by a power law structure for MBL systems, and how it can be used to identify the free theory that is closest to a given interacting model.

Prof. Dobrosavljević (Florida State University) addressed how disorder in strongly correlated systems can give rise to non-trivial localised states. It was shown that localised states are of great importance in explaining experimental results for these systems, since it is experimentally challenging to produce crystalline materials without some sort of disorder. Participants were given a whistle-stop tour of how DMFT can be extended to include disorder and its implications for the A15 compounds, the physics near the Mott transition and Friedel oscillations in the Fermi sea.

Participants were also able to present their work in contributed talks as well as two dedicated poster sessions. This rich range of contributions stimulated interesting discussion during the coffee breaks, poster sessions and the workshop dinner.

The organising committee are thankful to CANES for the opportunity to run the workshop as well as invaluable support. Similarly, we would like to thank all the participants, in particular those who contributed by presenting their work. Lastly, we’re grateful for the financial support by the EPSRC and our sponsor Overleaf.

For more information on the speakers, the workshop, and for slides and lecture capture, please visit: https://caneslocalisation.github.io