Hysteretic Electronic Phase Transitions in Correlated Charge-Density-Wave State of 1T-TaS2

TL;DR

This study reveals complex hysteretic electronic phase transitions in 1T-TaS2, showing how temperature-dependent interactions lead to diverse coexisting states within its charge-density-wave phases, advancing understanding of correlated quantum materials.

Contribution

It provides detailed spatial and temperature-dependent insights into the hysteretic phase transitions and emergent electronic states in 1T-TaS2 using VT-STM, highlighting the interplay of various electronic interactions.

Findings

Identification of spatial electronic phase transitions during temperature cycling.

Observation of coexistence and separation of electronic states within CDW phases.

Elucidation of the role of interlayer, intralayer, and electron-phonon interactions.

Abstract

Recently, many exotic electronic states, such as quantum spin liquid (QSL) and superconductivity (SC), have been extensively discovered and introduced in layered transition metal dichalcogenides 1T-TaS2 by controlling their complex correlated charge-density-wave (CDW) states. However, few studies have focused on its hysteretic electronic phase transitions based on the in-depth discussion of the delicate interplay among temperature-dependent electronic interactions. Here, we reported a sequence of spatial electronic phase transitions in the hysteresis temperature range of 1T-TaS2 via variable-temperature scanning tunneling microscopy (VT-STM). The emergence, evolution, coexistence, and separation of diverse novel electronic states within the commensurate CDW/triclinic CDW (CCDW/TCDW) phase are investigated in detail through the warming/cooling process. These novel emergent electronic states can be attributed to the delicate temperature-dependent competition and/or cooperation of interlayer interactions, intralayer electron-electron correlation, and electron-phonon (e-ph) coupling of 1T-TaS2. Our results not only provide a novel insight to understand the hysteretic electronic phase transitions of correlated CDW state, but also pave a way to realize more exotic quantum states by accurately and effectively controlling various interactions in correlated materials.