When two graphene lattices are overlaid and tilted, they can interfere to create a moiré pattern with a long period. At a small angle of about 1.1º, it was recently showed that the twisted bilayer graphene stack becomes superconducting. At this “magic” angle, the energy dispersion of electrons becomes flat and the interaction parameter becomes large. By tuning the carrier density, the twisted bilayer graphene stack becomes a Mott insulator. These properties are similar to those of cuprates and other high-temperature superconductors. Graphene has two key advantages compared to these materials. First, the band structure of monolayer graphene is simple and well understood. Second, the Fermi energy can be tuned by simply adjusting the voltage applied to the gate electrode in order to characterize the whole phase diagram of electrons. Recently, rhombohedral multilayer graphene has also attracted considerable interest, since it features faltbands and shows evidences of superconductivity. These recent advances show that graphene represents a promising platform for exploring unconventional superconductivity. It will be interesting to compare future progresses to what is known from other unconventional superconductors, such as VSe2 multilayer flakes and LaAlO3/SrTiO3 interfaces.
The goal of the Lavoisier Discussion is to stimulate discussions on this emerging topic and to create future collaborations. For this reason, considerable time will be left for discussions and round table debates.
This Lavoisier Discussion will be the occasion to gather the French and European groups interested in graphene flatbands. An important objective is to bridge the different scientific communities. This one-day workshop will set the frame for debating the current and future challenges in the field. In the spirit of the Lavoisier discussions, poster and oral presentations will be complemented by round table debates.
Registration : please send an email to LavoisierTwisted@gmail.com with the email subject "Lavoisier discussion registration". A short abstract should be added when applying for a contributed talk. The registration is free.
Deadline for registration 15/05/2019.
Schedule & Programme :
Wednesday 5 June 2018 at the Ecole Normale Supérieure in Paris