Probing the phase transition to a coherent 2D Kondo lattice

TL;DR

This study demonstrates the creation of a two-dimensional Kondo lattice in van der Waals heterostructures, revealing a phase transition to a coherent state with potential for exploring novel electronic phenomena.

Contribution

It introduces a method to realize a 2D Kondo lattice by stacking layered materials and provides experimental evidence of the phase transition to coherence.

Findings

Unambiguous demonstration of 2D Kondo lattice formation

Observation of a phase transition to a coherent state

Potential for exploring new correlated electronic states

Abstract

Strongly correlated materials exhibit exotic electronic states arising from the strong correlation between electrons. Dimensionality provides a tuning knob because thinning down to atomic thickness reduces screening effects and enhances electron correlations. In this work, a 2D Kondo lattice has been created by stacking a layer of 1T-TaS2 on a 2H-TaS2 crystal, which are bound by weak van der Waals interactions. By using high-resolution scanning tunnelling spectroscopy and density functional theory, we unambiguously demonstrate the formation of a 2D Kondo lattice from an ensemble of independent Kondo impurities present at higher temperatures. The possibility to create 2D Kondo lattices in van der Waals heterostructures paves the way for the exploration of unconventional metallic, magnetic and superconducting states not present in more standard correlated materials.