• Séminaire nano-électronique quantique
• Personne à contacter : Cecile Repellin ()
• Conférence Zoom : consulter le lien de connexion dans les emails d'annonce ou contacter l'organisateur

Résumé : Twisted bilayer graphene (tBG) and variants like twisted monolayer-bilayer graphene (tMBG) were proposed to be a platform for strongly correlated physics akin to the cuprate family. However, I will show that many of the observed interacting phenomena can be explained in terms of breaking of spin/valley symmetry. This can lead to a quantum anomalous Hall effect in the absence of a field, as I will show for tMBG [1]. In large magnetic fields the same spin- valley symmetry breaking leads to a series of Chern insulator states [2]. Finally, I will briefly discuss the possibility of genuine strong correlated physics in Moiré structures. [1] Rademaker, Protopopov, Abanin, Phys. Rev. Research, 2, 033150 (2020). [2] Saito, Ge, Rademaker, Watanabe, Taniguchi, Abanin, Young, Nature Physics, 108, 12233 (2021).

Liens :[Louk Rademaker]

• Personne à contacter :
• Conférence Zoom : consulter le lien de connexion dans les emails d'annonce ou contacter l'organisateur

Résumé : This thesis is dedicated to the study of ground states of an anyon gas in the large number of particle limit. In two-dimensional space there are possibilities for quantum statistics continuously interpolating between the bosonic and the fermionic one. Quasi-particles obeying such intermediate statistics are called anyons. They can be described as ordinary bosons and fermions with interactions through long-range magnetic potentials, generated by magnetic charges carried by each particle. We study the almost-bosonic and almost-fermionic limit. We obtain rigorous results for the convergence of their ground state energies and the associated minimizers to those of effective models. The ground state of almost-bosonic anyons converges to the infimum of a Hartree-like functionnal and its minimizers to a convex superposition of factorized pure states. The particles behave like independent, identically distributed bosons interacting via a self-consistent magnetic field. The ground state energy of almost-fermionic anyons converges to the infimum of a Thomas-Fermi energy and its minimizers to measures associated with the corresponding semi-classical problem. More precisely, the ground state of our Hamiltonian converges to that of a classical modified Vlasov energy whose minimization leads to the Thomas-Fermi functional. The Vlasov energy is endowed with a self-consistent magnetic field, a landmark of anyonic statistics. The ground state of the Vlasov energy displays anyonic behavior in its momentum distribution.

• Séminaire nano-électronique quantique
• Personne à contacter :
• location ROOM