In-Plane Conductivity Anisotropy in Underdoped Cuprates in the Spin-Charge Gauge Approach

TL;DR

This paper uses a spin-charge gauge theory to explain the anisotropic in-plane AC and DC conductivity features observed in underdoped cuprates, aligning well with experimental data.

Contribution

It provides a self-consistent theoretical explanation for the anisotropic conductivity phenomena in underdoped cuprates using the spin-charge gauge approach.

Findings

Broad peak in far-infrared in-plane AC conductivity

Significant low-temperature anisotropy in AC and DC conductivities

Agreement with experimental observations

Abstract

Applying the recently developed spin-charge gauge theory for the pseudogap phase in cuprates, we propose a self-consistent explanation of several peculiar features of the far-infrared in-plane AC conductivity, including a broad peak as a function of frequency and significant anisotropy at low temperatures, along with a similar temperature-dependent in-plane anisotropy of DC conductivity in lightly doped cuprates. The anisotropy of the metal-insulator crossover scale is considered to be responsible for these phenomena. The obtained results are in good agreement with experiments. An explicit proposal is made to further check the theory.