Fermi surface reconstruction without symmetry breaking and novel quantum criticality in a simple model of electron fractionalization.

by Dr. Snir Gazit

HUJI

at Condensed Matter Seminar

Mon, 29 Nov 2021, 11:30
Sacta-Rashi Building for Physics (54), room 207

Abstract

Orthogonal fermions present the simplest form of electronic fractionalization, where physical (gauge- neutral) electrons split into a local product of spinful fermions and Ising matter fields. This construction naturally gives rise to an emergent Ising gauge structure, which in two space dimensions is potentially topologically ordered. Using sign problem-free quantum Monte Carlo simulations, we investigate a lattice model of orthogonal fermions coupled to Ising gauge fields and matter fields. By tuning microscopic parameters, we control the fractionalization process and establish the resulting phase diagram. In particular, we demonstrate a transition between small and large Fermi surfaces, which crucially does not involve translational symmetry breaking, a phenomenon that violates the conventional Luttinger theorem. In addition, we uncover a new form of a deconfined critical point between phases with conventional and topological orders.

Created on 28-11-2021 by Meidan, Dganit (dganit)
Updaded on 28-11-2021 by Meidan, Dganit (dganit)