Particle-Hole Asymmetry in Doped Mott Insulators: Implications for Tunneling and Photoemission Spectroscopies

TL;DR

This paper derives exact sum rules for the one-particle spectral function in strongly correlated systems, explaining the particle-hole asymmetry observed in tunneling and photoemission experiments, with implications for high Tc superconductors.

Contribution

It provides new exact sum rules and a variational approach to understand particle-hole asymmetry in doped Mott insulators, linking theory to experimental spectroscopic observations.

Findings

Reveals fundamental asymmetry in spectral functions due to strong correlations

Explains tunneling spectra asymmetry in high Tc superconductors

Offers a method to estimate local doping variations in inhomogeneous materials

Abstract

In a system with strong local repulsive interactions it should be more difficult to add an electron than to extract one. We make this idea precise by deriving various exact sum rules for the one-particle spectral function independent of the details of the Hamiltonian describing the system and of the nature of the ground state. We extend these results using a variational ansatz for the superconducting ground state and low lying excitations. Our results shed light on the striking asymmetry in the tunneling spectra of high Tc superconductors and should also be useful in estimating the local doping variations in inhomogeneous materials.