Origin of the pseudogap and its influence on superconducting state

TL;DR

This paper proposes an effective Hamiltonian to explain the pseudogap in underdoped cuprates, attributing it to dressed holes in an antiferromagnetic background, and distinguishes it from superconductivity.

Contribution

It introduces a new effective Hamiltonian model that explains the pseudogap as separate from superconductivity in cuprates.

Findings

Qualitative agreement with ARPES measurements of the pseudogap and superconducting gaps.

The pseudogap arises from dressed holes in an antiferromagnetic background.

A two-gap scenario explains the relationship between the pseudogap and superconducting gap.

Abstract

When holes move in the background of strong antiferromagnetic correlation, two effects with different spatial scale emerge, leading to a much reduced hopping integral with an additional phase factor. An effective Hamiltonian is then proposed to investigate the underdoped cuprates. We argue that the pseudogap is the consequence of dressed hole moving in the antiferromagnetic background and has nothing to do with the superconductivity. The momentum distributions of the gap are qualitatively consistent with the recent ARPES measurements both in the pseudogap and superconducting state. Two thermal qualities are further calculated to justify our model. A two-gap scenario is concluded to describe the relation between the two gaps.