Signatures of the Fermi surface reconstruction of a doped Mott insulator in a slab geometry

TL;DR

This paper studies how surface effects and doping induce Fermi surface reconstruction in a doped Mott insulator using a slab geometry, revealing layer-dependent electronic structure changes and new diagnostic tools.

Contribution

It introduces a method to detect Fermi surface topology changes in doped Mott insulators through surface-induced Friedel oscillations and a novel diagnostic quantity, avoiding momentum space periodization.

Findings

Surface layers show hole-like pockets, inner layers show electron-like Fermi surface.

Friedel oscillations reveal signatures of Fermi surface reconstruction.

A new quantity diagnoses Fermi surface changes without momentum space periodization.

Abstract

We investigate a hole-doped Mott insulator in a slab geometry using the dynamical cluster approximation. We show that the enhancement of the correlation strength at the surface results in the remarkable evolution of the layer-projected Fermi surface, which exhibits hole-like pockets in the superficial layers, but gradually evolves into a single electron-like surface in the innermost layers. We further analyze the behavior of the Friedel oscillations induced by the surface and identify distinct signatures of the Fermi surface reconstruction as function of hole-doping. In addition, we introduce a computationally tractable quantity that diagnoses the same Fermi surface variation by the concurrent breakdown of Luttinger's theorem. Both the latter quantity and the Friedel oscillations serve as reliable indicators of the change in Fermi surface topology, without the need for any periodization in momentum space.