Pressure-induced insulator-to-metal transition in low-dimensional TiOCl

TL;DR

This study investigates how applying pressure induces an insulator-to-metal transition in TiOCl, revealing significant changes in optical properties and electronic structure at high pressure.

Contribution

It provides the first detailed optical analysis of pressure-induced electronic phase transition in TiOCl, highlighting the evolution of its optical conductivity and orbital excitations.

Findings

Suppression of transmittance above 12 GPa

Abrupt increase in near-infrared reflectance at transition

Pressure-dependent shifts in orbital excitations

Abstract

We studied the transmittance and reflectance of the low-dimensional Mott-Hubbard insulator TiOCl in the infrared and visible frequency range as a function of pressure. The strong suppression of the transmittance and the abrupt increase of the near-infrared reflectance above 12 GPa suggest a pressure-induced insulator-to-metal transition. The pressure-dependent frequency shifts of the orbital excitations, as well as the pressure dependences of the charge gap and the spectral weight of the optical conductivity above the phase transition are presented.