Petr Stepanov
ICFO
Research group: Quantum Nano-Optoelectronics and Low-Dimensional Quantum Materials
ICFO
Research group: Quantum Nano-Optoelectronics and Low-Dimensional Quantum Materials
I am a condensed matter experiment physicist with the focus on graphene and 2D materials. My main interest is to study electron transport, optical and related phenomena in a variety of condensed matter systems: magic angle twisted bilayer graphene; spin transport through graphene antiferromagnets; semiconductors; ferromagnets; superconductors.
My research is being focused on studying properties of magic angle twisted bilayer graphene (MATBG), a novel strongly correlated system discovered experimentally by the group at the Massachusetts Institute of Technology in 2018. By twisting two crystallographically aligned layers of graphene by “magic” angle 1.1°, the MIT group achieved a unique hybridization of the bands, which lead to formation of two narrow flat bands hosting strongly correlated physics. My major accomplishment in this field is described in paper published in Nature magazine in July 2020. I have used electron transport studies to demonstrate a method to control electron-electron interactions in MATBG by varying its proximity to a conductive graphite sheet and I applied this method to observe the quenching of strongly correlated physics in this system. In particular, I observed that correlated insulators disappear in the samples with the most screening, while the superconductivity survives. This is a major advance for the tunable electronic matter. In addition, it calls for the re-examination of the often assumed “parent-and-child” relation between strongly correlated phases in MATBG.