Multiband Semimetallic Electronic Structure of Superconducting Ta2PdSe5

TL;DR

This study uses density functional calculations to analyze the electronic structure of Ta2PdSe5, revealing its semimetallic nature and potential for two-band superconductivity, with implications for understanding its superconducting properties.

Contribution

First detailed electronic structure analysis of Ta2PdSe5 showing its semimetallic and multiband superconducting characteristics.

Findings

Fermi surface consists of two disconnected sheets from chalcogenide p states.

Material is a semimetallic superconductor with specific electron and hole counts.

Supports the presence of two-band superconductivity despite some discrepancies.

Abstract

We report the electronic structure and related properties of the superconductor Ta2PdSe5 as determined from density functional calculations. The Fermi surface has two disconnected sheets, both derived from bands of primarily chalcogenide p states. These are a corrugated hole cylinder and and a heavier complex shaped electron sheet. The sheets contain 0.048 holes and a compensating number of electrons per formula unit, making the material a semimetallic superconductor. The results support the presence of two band superconductivity, although a discrepancy in the specific heat is noted. This discrepancy is discussed as a possible consequence of Pd deficiency in samples.