Robust quantum transport at particle-hole symmetry

¹ Institute of Nuclear Physics, Polish Academy of Sciences - 31-342 Kraków, Poland
² Department of Physics, Stockholm University, AlbaNova University Center - 106 91 Stockholm, Sweden
³ Institut für Physik, Universität Augsburg - D-86135 Augsburg, Germany

^(a) ipsita.mandal@gmail.com (corresponding author)

Received: 11 June 2021
Accepted: 3 August 2021

Abstract

We study quantum transport in disordered systems with particle-hole symmetric Hamiltonians. The particle-hole symmetry is spontaneously broken after averaging with respect to disorder, and the resulting massless mode is treated in a random-phase representation of the invariant measure of the symmetry group. We compute the resulting fermionic functional integral of the average two-particle Green's function in a perturbation theory around the diffusive limit. The results up to two-loop order show that the corrections vanish, indicating that the diffusive quantum transport is robust. On the other hand, the diffusion coefficient depends strongly on the particle-hole symmetric Hamiltonian we choose to study. This reveals a connection between the underlying microscopic theory and the classical long-scale metallic behaviour of these systems.