Electric transport in doped Mott insulators dictated by a non-Ioffe-Larkin composition rule and spinons

TL;DR

This paper investigates electric transport in doped Mott insulators, revealing a non-Ioffe-Larkin composition rule influenced by topological gauge structures, with distinct behaviors in pseudogap and high-temperature phases.

Contribution

It introduces a non-Ioffe-Larkin composition rule for charge transport governed by a topological gauge structure and explores the role of chiral spinons in different phases of doped Mott insulators.

Findings

Vanishing resistivity in the superconducting phase due to spinon confinement.

Low-temperature resistivity divergence when spinon confinement is disrupted by magnetic fields.

Linear-temperature resistivity in the high-temperature spin-disordered phase.

Abstract

The electric resistivity is examined in the constrained Hilbert space of a doped Mott insulator, which is dictated by a non-Ioffe-Larkin composition rule due to the underlying mutual Chern-Simons topological gauge structure. In the low-temperature pseudogap phase, where holons remain condensed while spinons proliferate, the charge transport is governed by a chiral spinon excitation, comprising a bosonic spin-$1/2$ at the core of a supercurrent vortex. It leads to a vanishing resistivity with the ``confinement'' of the spinons in the superconducting phase but a low-$T$ divergence of the resistivity once the spinon confinement is disrupted by external magnetic fields. In the latter, the chiral spinons will generate a Hall number $n_H =$ doping concentration $ \delta$ and a Nernst effect to signal an underlying long-range entanglement between the charge and spin degrees of freedom. Their presence is further reflected in thermodynamic quantities such as specific heat and spin susceptibility. Finally, in the high-temperature spin-disordered phase, it is shown that the holons exhibit a linear-$T$ resistivity by scattering with the spinons acting as free local moments, which generate randomized gauge fluxes as perceived by the charge degree of freedom.