On the origin of the pseudogap in underdoped cuprates

TL;DR

This paper uses Quantum Monte Carlo simulations to investigate the microscopic origin of the pseudogap in underdoped cuprates, providing evidence that spin-charge separation explains the phenomenon better than other proposed scenarios.

Contribution

The study offers the first numerical evidence supporting spin-charge separation as the cause of the pseudogap in the 2D Hubbard model.

Findings

Supports spin-charge separation as the pseudogap origin

Contradicts preformed pairs and stripe scenarios

Rules out quasiparticle coupling to spin fluctuations

Abstract

We investigate the microscopic origin of the pseudogap in the weakly doped 2D Hubbard model using Quantum Monte Carlo within the dynamical cluster approximation. We compare our results with proposed scenarios for the pseudogap. All our numerical evidence is in favor of spin-charge separation as described in the resonating valence bond picture as the cause of the pseudogap behavior. Scenarios of "preformed pairs", the coupling of quasiparticles to antiferromagnetic spin-fluctuations and stripes are inconsistent with our results.