Three prerequisites for high-temperature superconductivity in t-PtBi$_2$

Abstract

Although the generic mechanism behind high-temperature superconductivity remains notoriously elusive, a set of favorable conditions for its occurrence in a given material has emerged: (i) the electronic structure should have a very high density of states near the Fermi level; (ii) electrons need to be susceptible to a sizable interaction with another degree of freedom to ensure pairing themselves; (iii) the ability to fine-tune some of the system properties significantly helps maximising the critical temperature. Here, by means of high-resolution ARPES, we show that all three criteria are remarkably fulfilled in trigonal platinum bismuthide (t-PtBi$_2$). Specifically, this happens on its surface, which hosts topological surface states known as Fermi arcs. Our findings pave the way for the stabilisation and optimisation of high-temperature superconductivity in this topological material.