Anomalous metals: from "failed superconductor" to "failed insulator"

Abstract

Resistivity saturation is found on both superconducting and insulating sides of an "avoided" magnetic-field-tuned superconductor-to-insulator transition (H-SIT) in a two-dimensional In/InO${}_x$ composite, where the anomalous metallic behaviors cut off conductivity or resistivity divergence in the zero-temperature limit. The granular morphology of the material implies a system of Josephson junctions (JJ) with a broad distribution of Josephson coupling E${}_J$ and charging energy E${}_C$ , with a H-SIT determined by the competition between E${}_J$ and E${}_C$ . By virtue of self-duality across the true H-SIT, we invoke macroscopic quantum tunneling effects to explain the temperature-independent resistance where the "failed superconductor" side is a consequence of phase fluctuations and the "failed insulator" side results from charge fluctuations. While true self-duality is lost in the avoided transition, its vestiges are argued to persist, owing to the incipient duality of the percolative nature of the dissipative path in the underlying random JJ system.

10 pages, 7 figures, including supplementary

References in corpus (7)

• Nature of the superconductor-insulator transition in disordered superconductors
• Theory of quantum metal to superconductor transitions in highly conducting systems
• Particle-hole symmetry reveals failed superconductivity in the metallic phase of two-dimensional superconducting films
• Anomalous metals: from "failed superconductor" to "failed insulator"
• Dissipative phases across the superconductor-to-insulator transition
• Superconductor-insulator transitions in three-dimensional indium-oxide at high pressures
• Compensation driven superconductor-insulator transition

Cited by in corpus (6)

• Electrically controlled superconductor-insulator transition and giant anomalous Hall effect in kagome metal CsV3Sb5 nanoflakes
• Quantum phase transitions in two-dimensional superconductors: a review on recent experimental progress
• Anomalous metals: from "failed superconductor" to "failed insulator"
• The Berezinskii-Kosterlitz-Thouless Transition and Anomalous Metallic Phase in a Hybrid Josephson Junction Array
• Voltage-tuned anomalous-metal to metal transition in hybrid Josephson junction arrays
• Gapless superconductivity in the low-frequency electrodynamic response of two-dimensional granular In/InO${}_x$ composites