Quantum criticality in graphene – Twisted or not

Datum

12.05.2025

Zeit

10:00 - 11:00

Sprecher

Prof. Arindam Ghosh

Zugehörigkeit

Indian Institute of Science, Bangalore

Sprache

en

Hauptthema

Materialien

Host

Martina Javorka

Beschreibung

The Dirac electrons in a clean layer of graphene are expected to interact strongly with each other because they are three hundred times slower than photons in free space. The speed can be reduced even more in twisted bilayer graphene due to repulsion and flattening of the low-energy electronic bands at specific angles, or the magic angle. This led to many new quantum phases in twisted layers during recent years. In this talk, I shall give a few snapshots of our work in realizing and detecting emergent quantum many-body phases in graphene, as a result of strong Coulomb interaction between the electrons. I shall explain our experimental approach in detecting such phases, which combine multiple experimental techniques, and in particular, augment standard electrical transport with thermal and thermoelectric characterization. I shall show how strong interaction leads to the breakdown of the semiclassical framework of thermoelectricity in twisted bilayers, or that of the Widemann-Franz law in very high-quality graphene where the electron-electron scattering becomes more frequent than the scattering of electrons by phonons or disorder. We believe these experiments will lead to a new strategy to exploit high-quality graphene as a testing bed for some of the unifying concepts in physics.

Links

• Seminars at the IFW

Letztmalig verändert: 12.05.2025, 07:39:27