Condensed Matter Seminar

Spin-orbit coupled graphene multilayers: correlations, superconductivity and topology

Abstract:  Crystalline graphene multilayers present a rich playground to explore correlated electronic phenomena in an ultra-clean setting, free of the inhomogeneities ubiquitous in their twisted counterparts. For instance, Bernal bilayer graphene (BLG) and rhombohedral trilayer graphene both exhibit several symmetry-broken metallic phases at low temperature, as well as superconductors with different pairing symmetries. Moreover, placing a WSe2 monolayer on BLG was shown to promote Cooper pairing to an extraordinary degree, with an order-of-magnitude enhancement of Tc [1].

Quantum Metric in 2D Superconductors and Exciton Condensates

Abstract:

In the past two decades some of the most interesting developments in condensed matter physics have resulted form the careful treatment of the effects arising from the Berry curvature of many-body ground states. The Berry curvature can be thought as the imaginary part of a complex tensor. The real part of this tensor is the quantum metric. In this talk I will show how the quantum metric affects the properties of superconductivity and exciton condensates in 2D flat band systems, and present some results specific to the case of twisted bilayer graphene.

SU(N)-symmetric density matrix renormalization group

Abstract:

There is a lot of interest in finding and identifying novel

quantum materials. We here focus on d1 materials with a

strong spin-orbit coupling, which are supposed to realize a much

higher symmetry than SU(2), an emergent SU(4) symmetry [1,2].

In fact, α-ZrCl3 is expected to host the SU(4) Heisenberg model

on the honeycomb lattice with a large frustration [3]. These

SU(4) materials potentially realize a new type of spin liquids,

a gapped Z4 spin liquid [4]. We present new density matrix

Pages

Subscribe to RSS - Condensed Matter Seminar