Resistivity of high pressure phosphorus phases

TL;DR

This paper investigates the electrical resistivity of different high-pressure phases of phosphorus, revealing phase-dependent electronic properties and highlighting discrepancies between theoretical predictions and experimental results.

Contribution

It provides new experimental resistivity data across phosphorus phases under pressure and discusses the mismatch with theoretical models.

Findings

Black phosphorus becomes metallic and superconducting at high pressure.

A17 phase transitions from narrow-gap semiconductor to topological metal.

Significant discrepancy between theoretical calculations and experimental resistivity measurements.

Abstract

Simple cubic (sc) black phosphorus (denoted BP), stable at P>10GPa, seems an ordinary metal. It has electron-phonon-driven superconductivity with Tc 5-10 K. The A17 phase, stable at atmospheric pressure, has a narrow gap, becomes semimetallic at P=1 GPa, and has a smooth transition to topological metal behavior at P ~ 5 GPa. The A7 phase, stable for 5<P<10 GPa, is metallic, superconducting, and less conventional than the sc phase. Some insights are extracted from analysis of resistivity versus temperature at various pressures. A surprising order-of-magnitude disagreement between theory and experiment is discussed.