Metal-insulator transition in YHx: scaling of the sub-THz conductivity

TL;DR

This study investigates the frequency-dependent conductivity in YHx across the metal-insulator transition, revealing that sub-THz conductivity aligns with dc data in the metallic phase, challenging simple quantum-phase transition models.

Contribution

First measurement of frequency scaling of conductivity in YHx, providing new insights into the quantum nature of the metal-insulator transition.

Findings

Sub-THz conductivity matches dc data in metallic phase

Scaling laws indicate quantum characteristics of transition

Results challenge simple quantum-phase transition models

Abstract

The established scaling laws of the conductivity with temperature and doping are strong indications for the quantum nature of the metal-insulator transition in YH$_x$. Here we report the first results on the frequency scaling of the conductivity. Samples were brought from the insulating to the metallic phase by carrier doping via illumination. In the metallic phase, the sub-terahertz conductivity coincides with the dc data. These results do not agree with the simplest picture of a quantum-phase transition.