Two-dimensional Superconductivity from Dimerization of Atomically Ordered AuTe2Se4/3 Cubes

TL;DR

This paper reports the discovery of two-dimensional superconductivity in bulk AuTe2Se4/3 achieved through atomic dimerization, revealing quasi-2D behavior and potential for topological phenomena.

Contribution

It demonstrates 2D superconductivity in a bulk compound via atomic dimerization, linking structural changes to emergent quantum properties.

Findings

Superconductivity at 2.85 K observed.

Quasi-2D nature confirmed by BKT transition.

Strong electron-phonon coupling suggested by Fermi surface nesting.

Abstract

The emergent phenomena such as superconductivity and topological phase transitions can be observed in strict two-dimensional crystalline matters. Artificial interfaces and one atomic thickness layers are typical 2D materials of this kind. Although having 2D characters, most bulky layered compounds, however, do not possess these striking properties. Here, we report the 2D superconductivity in bulky AuTe2Se4/3,where the reduction in dimensionality is achieved through inducing the elongated covalent Te-Te bonds. The atomic-resolution images reveal that the Au, Te and Se are atomically ordered in a cube, among which are Te-Te bonds of 3.18 A and 3.28 A. The superconductivity at 2.85 K is discovered, which is unraveled to be the quasi-2D nature owing to the BKT topological transition. The nesting of nearly parallel Fermi sheets could give rise to strong electron-phonon coupling. It is proposed to further depleting the thickness could result in more topologically-related phenomena.