Materials-by-Design: Emergence of Superconductivity and Robust Topological State in Bi_xTaS₂

The quest for tailored materials with extraordinary electronic properties has been a driving force in condensed matter physics. Recent advancements in computational materials science have opened up the exciting prospect of materials-by-design, where the emergence of unique electronic phases can be predicted and engineered. In this presentation, we explore the remarkable case of bismuth tantalum disulfide (Bi_xTaS₂), a materials-by-design success story in which the deliberate manipulation of the crystal structure leads to the emergence of superconductivity and a robust topological state.

Our research begins with formulating a compound hosting a heavy metal (to induce strong SOC and charge transfer), in which the metal Bi as an intercalant and TaS₂ as a host seem to be a reasonable combination. Through crystal search evolution algorithms, we arrived at a suitable system of Bi_xTaS₂. Using theoretical DFT simulations and carefully synthesizing, we arrived at a specific crystal lattice that can host a unique combination of electronic states. We uncover the distinctive electronic structure of this compound, which provides fertile ground for the emergence of intriguing phenomena.

We will discuss our experimental findings, which confirm the presence of superconductivity in Bi_xTaS₂. Furthermore, the deliberate design of the material's structure results in observing a topologically non-trivial electronic state characterized by surface states robust to perturbations.

We will delve into the fundamental understanding of the interplay between superconductivity, topological properties, structure, and chemistry of Bi in TaS₂, offering insights into the mechanisms behind these phenomena. We will also discuss the broader implications of our materials-by-design approach, which advances our understanding of condensed matter physics and opens up new avenues for creating custom-tailored materials with desired electronic properties for future applications in quantum computing, energy storage, and beyond.