A5078437279- Graphene research and applications
- Quantum and electron transport phenomena
- Topological Materials and Phenomena
- Quantum Electrodynamics and Casimir Effect
- Thermal properties of materials
University of Jyväskylä
2018-2020
Recent experiments show how a bilayer graphene twisted around certain magic angle becomes superconducting as it is doped into region with approximate flat bands. We investigate the mean-field $s$-wave state in such system and evolves twist tuned, function of doping level. argue that part experimental findings could well be understood to result from an attractive electron--electron interaction mediated by electron--phonon coupling, but flat-band nature excitation spectrum makes also...
We study superconductivity of twisted bilayer graphene with local and non-local attractive interactions. obtain the superfluid weight Berezinskii-Kosterlitz-Thouless (BKT) transition temperature for microscopic tight-binding low-energy continuum models. predict qualitative differences between interaction schemes which could be distinguished experimentally. In flat band limit where pair potential exceeds width we show that BKT are determined by multiband processes quantum geometry band.
In the search of high-temperature superconductivity one option is to focus on increasing density electronic states. Here we study both normal and $s$-wave superconducting state properties periodically strained graphene, which exhibits approximate flat bands with a high states, flatness tunable by strain profile. We generalize earlier results regarding one-dimensional harmonic arbitrary periodic fields, further extend calculating superfluid weight Berezinskii-Kosterlitz-Thouless (BKT)...