Superconducting PdTe Thin Film Via Topotactic Transformation, Toward Topological Superconductors

TL;DR

This paper reports the successful growth of high-quality superconducting PdTe thin films via molecular beam epitaxy, using a topotactic transformation, advancing the development of topological superconductors for quantum computing.

Contribution

It introduces a novel method to produce PdTe thin films with bulk-like superconducting properties through a topotactic transformation during MBE growth.

Findings

PdTe films exhibit a sharp superconducting transition at ~4.43 K

Films show two-dimensional superconducting behavior

PdTe films are structurally confirmed as NiAs-type and air-stable

Abstract

Topological superconductors (TSCs) hosting Majorana zero modes (MZMs) offer a pathway to fault-tolerant quantum computation. PdTe is a promising TSC candidate due to its topological surface states and a reasonable superconducting critical temperature of ~4.5 K. However, it has been challenging to grow PdTe thin films with bulk-like superconducting properties. Here, we show that high-quality, superconducting PdTe thin films can be grown using molecular beam epitaxy (MBE). The films exhibit a sharp superconducting transition (T_onset = 4.43 K with transition width of 0.06 K), comparable to that of bulk crystals. This was made possible via a topotactic transformation from a PdTe_2 buffer layer to a PdTe phase by growing Pd on top under Te-deficient conditions. Structural and transport analyses confirm the NiAs-type structure of PdTe, as well as its two-dimensional superconducting behavior and excellent air stability. These findings suggest that the MBE-grown PdTe films and their heterostructures are a promising platform for topological superconductivity and Majorana physics.