A time-domain phase diagram of metastable states in a charge ordered quantum material

TL;DR

This study maps the evolution of metastable states in a quantum material over a wide range of timescales using advanced optical and microscopy techniques, revealing dynamic phase transition pathways.

Contribution

It introduces a time-domain phase diagram for metastable states in a charge-ordered quantum material, linking temporal evolution with phase transition mechanisms.

Findings

Mapped metastable states from femtoseconds to seconds

Identified different transition mechanisms on various timescales

Provided experimental data aligning with theoretical phase diagrams

Abstract

Metastable self-organized electronic states in quantum materials are of fundamental importance, displaying emergent dynamical properties that may be used in new generations of sensors and memory devices. Such states are typically formed through phase transitions under non-equilibrium conditions and the final state is reached through processes that span a large range of timescales. By using time-resolved optical techniques and femtosecond-pulse-excited scanning tunneling microscopy (STM), the evolution of the metastable states in the quasi-two-dimensional dichalcogenide 1T-TaS2 is mapped out on a temporal phase diagram using the photon density and temperature as control parameters on timescales ranging from 10^(-12) to 10^3 s. The introduction of a time-domain axis in the phase diagram enables us to follow the evolution of metastable emergent states created by different phase transition mechanisms on different timescales, thus enabling comparison with theoretical predictions of the phase diagram and opening the way to understanding of the complex ordering processes in metastable materials.