Theory Group Adrian Kantian
The group's research focusses on developing basic theory that would allow to engineer unconventional superconductors (USC) on purpose, with controlled properties, using low-dimensional systems as building blocks. Currently, the USCs (in which electrons pair up from repulsive electron interactions) are of intense fundamental and applied interest, but the basic mechanisms behind them are poorly understood. This has prevented e.g. systematically raising critical temperatures for superconductivity in USC materials.
In contrast, this group develops theory that will allow to build up USCs by coupling low-dimensional materials to each other or to external reservoirs. Their properties, including the mechanisms behind USC, can then be fully understood and predicted, allowing to systematically design better USCs, and to extend superconductivity to micron-length 1D nanowires.
The theories behind this will further allow to understand the as-yet unresolved mechanisms behind many existing quasi-1D USC materials, such as the Bechgaard and Fabre salts, the Sr-ladder “telephone number” compounds, and chromium pnictide.
This research makes extensive use of the parallelized density matrix renormalization group (DMRG) codes developed in the MAQUIS collaboration between the University of Geneva and ETH Zürich. It is complemented by Quantum Monte Carlo and DMFT methods and the analytical techniques of bosonization combined with RG treatments, as well as functional RG.
The groups work is supported by the European Research Council through a Starting Grant, as well as Uppsala University.
The groups PI further maintains interest and work on other quantum many-body states and systems, such as 1D bilayer exciton condensates, chiral quantum spin liquids, many-body localized systems and doped graphene nanoribbons, as well as many-body state preparation for quantum emulation in ultracold atoms confined to optical lattices and the study of mobile impurities in 1D quantum liquids.