Pressure-induced Superconductivity in Crystalline Boron Nanowires

TL;DR

This study demonstrates that boron nanowires exhibit pressure-induced superconductivity at significantly lower pressures than bulk boron, with their critical temperature increasing as pressure rises, highlighting size effects in nanostructures.

Contribution

It reveals that boron nanowires become superconducting under high pressure at lower thresholds than bulk boron, emphasizing the influence of nanoscale size effects.

Findings

BNWs show semiconductor-metal transition at lower pressure than bulk boron.

Superconductivity with Tc=1.5 K appears at 84 GPa in BNWs.

Tc increases with rising pressure.

Abstract

We report high-pressure induced superconductivity in boron nanowires (BNWs) with rhombohedral crystal structure. Obviously different from bulk rhombohedral boron, these BNWs show a semiconductor-metal transition at much lower pressure than bulk boron. Also, we found these BNWs become superconductors with Tc=1.5 K at 84 GPa, at the pressure of which bulk boron is still a semiconductor, via in-situ resistance measurements in a diamond anvil cell. With increasing pressure, Tc of the BNWs increases. The occurrence of superconductivity in the BNWs at a pressure as low as 84 GPa probably arises from the size effect.