Enhanced superconductivity in bilayer PtTe$_2$ by alkali-metal intercalations

TL;DR

This study demonstrates that alkali-metal intercalation, specifically rubidium, significantly enhances superconductivity in bilayer PtTe2, achieving a Tc of 8 K, and highlights its potential for exploring two-dimensional quantum physics.

Contribution

The paper introduces a theoretical approach showing how rubidium intercalation boosts superconductivity in bilayer PtTe2, a novel method for tuning 2D superconductors.

Findings

Rubidium intercalation increases Tc to 8 K in bilayer PtTe2.

Intercalation enhances interlayer coupling and electron density at Fermi energy.

Potassium intercalation yields similar superconducting properties.

Abstract

Layered platinum tellurium (PtTe2) was recently synthesized with controllable layer numbers down to a monolayer limit. Using ab initio calculations based on anisotropic Midgal-Eliashberg formalism, we show that by rubidium (Rb) intercalation, weak superconductivity in bilayer PtTe2 can be significantly boosted with superconducting Tc = 8 K in the presence of spin-orbit coupling (SOC). The intercalant on one hand mediates the interlayer coupling and serves as an electron donor, leading to large density of states at Fermi energy. On the other hand, it increases the mass-enhancement parameter with electron-phonon coupling strength comparable to that of Pt. The potassium intercalated bilayer PtTe2 has a comparable Tc to the case of Rb intercalation. The relatively high Tc with SOC combined with experimental accessible crystal structures suggest that these superconductors are promising platforms to study the novel quantum physics associated with two-dimensional superconductivity, such as the recently proposed type-II Ising superconductivity.