Alberto De la Torre1
Northeastern University1
In materials with competing order parameters, quenching across a phase transition can lead to the system being trapped in a long-lived metastable phase, even if it is not the global free-energy minimum. Examples of this phenomenology can be found over multiple energies and length scales - from the evolution of the known Universe to supercooled liquids [1]. 1T-TaS<sub>2</sub>, a layered dichalcogenide, is a unique platform for studying dynamic phase transitions in quantum materials [2]. Upon quenching 1T-TaS<sub>2</sub> after excitation with an ultrafast laser pulse, a low-temperature metallic metastable phase (H-CDW) emerges [3], which is different from any of the charge density wave (CDW) phases characterizing its thermodynamic phase diagram. I will show that a new metastable insulating phase with similar scattering signatures to the H-CDW [4] can be stabilized by intermediate quenching rates [5]. I will discuss the implications of this new phase in the controversy surrounding the presence of Mott physics and the role of c-axis correlations [6] in the equilibrium ground state of 1T-TaS<sub>2</sub>.<br/><br/>[1] Zhiyuan Sun and Andrew J. Millis Phys. Rev. X 10, 021028 (2020)<br/>[2] B. Sipos et al., Nat. Mat. 7, 960 (2008)<br/>[3] L. Stojchesvka et al., Science 344, 177 (2014)<br/>[4] Stahl et al., Nat. Commun. 11, 1247 (2020)<br/>[5] AdlT et al., in preparation<br/>[6] S-H Lee et al., PRL 122, 106404 (2019)