Quantum billiards with correlated electrons confined in triangular transition metal dichalcogenide monolayer nanostructures created by laser quench

TL;DR

This study investigates quantum interference effects of correlated electrons in laser-created monolayer nanostructures, revealing how confinement and correlations destabilize certain electron states and produce mixed localized and itinerant behaviors, including quantum scars.

Contribution

It introduces a novel method of creating atomic-scale monolayer nanostructures via laser quench and analyzes the resulting correlated electron quantum interference effects.

Findings

Confinement destabilizes Wigner/Mott crystal ground states.

Mixed itinerant and localized electron states observed.

Quantum scars suggest classical trajectory-like interference patterns.

Abstract

Forcing systems though fast non-equilibrium phase transitions offers the opportunity to study new states of quantum matter that self-assemble in their wake. Here we study the quantum interference effects of correlated electrons confined in monolayer quantum nanostructures, created by femtosecond laser-induced quench through a first-order polytype structural transition in a layered transition-metal dichalcogenide material. Scanning tunnelling microscopy of the electrons confined within equilateral triangles, whose dimensions are a few crystal unit cells on the side, reveals that the trajectories are strongly modified from free-electron states both by electronic correlations and confinement. Comparison of experiments with theoretical predictions of strongly correlated electron behaviour reveals that the confining geometry destabilizes the Wigner/Mott crystal ground state, resulting in mixed itinerant and correlation-localized states intertwined on a length scale of 1 nm. Occasionally, itinerant-electron states appear to follow quantum interferences which are suggestive of classical trajectories (quantum scars). The work opens the path toward understanding the quantum transport of electrons confined in atomic-scale monolayer structures based on correlated-electron-materials.