Fragile three-dimensionality in the quasi-one-dimensional cuprate PrBa_2Cu_4O_8

TL;DR

This study investigates the fragile three-dimensional metallic state in PrBa₂Cu₄O₈, revealing how disorder and temperature induce a crossover from 3D Fermi-liquid behavior to localization when scattering surpasses interchain hopping.

Contribution

It demonstrates the experimental realization of a dimensional crossover in a cuprate, showing the critical role of disorder and scattering in the metal-insulator transition.

Findings

3D Fermi-liquid state at low temperatures in pure crystals

Localization occurs when scattering rate exceeds interchain hopping

Metal/insulator crossover is driven by carrier confinement to chains

Abstract

In this article we report on the experimental realization of dimensional crossover phenomena in the chain compound PrBa$_2$Cu$_4$O$_8$ using temperature, high magnetic fields and disorder as independent tuning parameters. In purer crystals of PrBa$_2$Cu$_4$O$_8$, a highly anisotropic three-dimensional Fermi-liquid state develops at low temperatures. This metallic state is extremely susceptible to disorder however and localization rapidly sets in. We show, through quantitative comparison of the relevant energy scales, that this metal/insulator crossover occurs precisely when the scattering rate within the chain exceeds the interchain hopping rate(s), i.e. once carriers become confined to a single conducting element.