Spin-charge gauge approach to metal-insulator crossover and transport properties in High-T$_c$ cuprates

TL;DR

This paper reviews a gauge theory approach to understanding the metal-insulator crossover and anomalous transport in high-temperature cuprates, linking theoretical models with experimental observations.

Contribution

It introduces a spin-charge gauge framework for the $t-J$ model, explaining the pseudogap and strange metal phases through gauge field interactions and composite particles.

Findings

Good agreement with experimental data for pseudogap and strange metal phases

Attribution of MIC to competition between antiferromagnetic order and charge carrier dynamics

Identification of composite particles with peculiar properties

Abstract

The spin-charge gauge approach to consider the metal-insulator crossover (MIC) and other anomalous transport properties in High-T$_c$ cuprates is briefly reviewed. A U(1) field gauging the global charge symmetry and an SU(2) field gauging the global spin-rotational symmetry are introduced to study the two-dimensional $t-J$ model in the limit $t\gg J$. The MIC as a clue to the understanding of the ``pseudogap'' (PG) phase, is attributed to the competition between the short-range antiferromagnetic order and dissipative motion of charge carriers coupled to the slave-particle gauge field. The composite particle formed by binding the charge carrier (holon) and spin excitation (spinon) via the slave particle gauge field exhibits a number of peculiar properties, and the calculated results are in good agreement with experimental data for both PG and ``strange metal'' phases. Connections to other gauge field approaches in studying the strong correlation problem are also briefly outlined.