Equilibrium Stabilization of a Hidden Phase Like Metallic State in 1T-TaS2

TL;DR

This study demonstrates that a hidden metallic phase in 1T-TaS2 can be stabilized at room temperature in exfoliated flakes, revealing new possibilities for controlling electronic states in layered materials.

Contribution

It shows that an equilibrium hidden-phase-like metallic state can be stabilized in exfoliated 1T-TaS2 flakes at room temperature, expanding understanding of phase control in correlated materials.

Findings

The hidden phase hosts a metallic band with Fermi-level spectral weight.

The hidden phase persists up to room temperature in exfoliated flakes.

It retains characteristic hybridization gaps despite metallic behavior.

Abstract

Electronic phases that lie outside the equilibrium ground state offer a route to explore competing configurations in correlated materials. In 1T-TaS2, ultrafast excitation accesses a metallic hidden phase that is distinct from the commensurate insulating ground state. Here we use angle-resolved photoemission spectroscopy to show that an equivalent electronic configuration is stabilized in exfoliated intermediate-thickness 1T-TaS2 flakes, where it persists up to room temperature before evolving through a different sequence of electronic transitions. This equilibrium hidden-phase-like state hosts a metallic band with finite Fermi-level spectral weight while retaining the characteristic hybridization gaps associated with the star-of-David band folding. These results establish a platform for controlling competing electronic states in layered materials, with implications for both quantum science and phase change technologies.