Orbital Effect of the Magnetic Field in Dynamical Mean-Field Theory

TL;DR

This paper demonstrates that orbital effects of magnetic fields can be incorporated into dynamical mean-field theory, enabling the study of magnetic field influences on interacting electron systems and revealing measurable phenomena like quantum oscillations and effective mass changes.

Contribution

It introduces a method to include orbital magnetic field effects in single-site dynamical mean-field theory for interacting systems.

Findings

Quantum oscillations in scattering rate are recovered.

Magnetic fields enable measurement of interaction-induced effective mass.

Orbital effects are significant in the Hofstadter butterfly regime.

Abstract

The availability of large magnetic fields at international facilities and of simulated magnetic fields that can reach the flux-quantum-per-unit-area level in cold atoms, calls for systematic studies of orbital effects of the magnetic field on the self-energy of interacting systems. Here we demonstrate theoretically that orbital effects of magnetic fields can be treated within single-site dynamical mean-field theory with a translationally invariant quantum impurity problem. As an example, we study the one-band Hubbard model on the square lattice using iterated perturbation theory as an impurity solver. We recover the expected quantum oscillations in the scattering rate and we show that the magnetic fields allow the interaction-induced effective mass to be measured through the single-particle density of states accessible in tunneling experiments. The orbital effect of magnetic fields on scattering becomes particularly important in the Hofstadter butterfly regime.