Topological superconductor candidates PdBi2Te4 and PdBi2Te5 from a generic ab initio strategy

Abstract

Superconducting topological metals (SCTMs) have recently emerged as a promising platform of topological superconductivity (TSC) and Majorana zero modes for quantum computation. Despite their importance in both fundamental research and applications, SCTMs are very rare in nature. Here, we propose a strategy to design SCTMs by intercalating the superconducting units into the topological insulators. A program that characterizes the superconducting BdG Chern number of 2D BdG Hamiltonian from ab initio calculations is also developed. Following this strategy, PdBi2Te5 and PdBi2Te4 are found to be experimentally synthesizable and ideal SCTMs. Chiral TSC could be realized in such SCTMs by incorporating topological surface states with Zeeman effect, which can be realized by an external magnetic field or in proximity to ferromagnetic insulator. Our strategy provides a new method for identifying the SCTMs and TSC candidates, and the program makes it possible to design and modulate the TSC candidates from ab initio calculations.

Pressure-driven dome-shaped superconductivity in topological insulator GeBi2Te4

“…These unexpected results have triggered to design new topological insulators with pseudobinary systems like nA IV B VI -mA 2V B 3VI (A IV = Ge, Sn, Pb; A 2V = Bi, Sb; B VI = Te, Se). Moreover, ternary PbBi 2 Te 4 and PbBi 2 Te 5 were predicted to be topological superconductor candidates by ab initio calculations [16]. Therefore, it is very meaningful to search for topological superconductors based on topological insulators in ternary systems.…”

Topological phase transition in compressed van der Waals superlattice heterostructure BiTeCl/HfTe2

“…[15] The proposed superconducting units are intercalated into topological insulators and form a strategy to search for topological superconductivity. [16] Interfacial superconductors offer a new route towards tunable superconductivity by chemical doping and electric field gating. [17] Hence, the natural combination of topology and superconductivity in layered heterostructures has advantages in terms of realizing topological superconductors.…”

Realization of 2D multiferroic with strong magnetoelectric coupling by intercalation: a first-principles high-throughput prediction

“…A family of 2D MA 2 Z 4 materials was obtained by intercalating a MoS 2 -type MZ 2 monolayer into InSe-type A 2 Z 2 bilayers. Among them, 2D MnBi 2 Te 4 is an AFM axion/Chern insulator with quantized anomalous Hall conductivity [21][22][23] , while PdBi 2 Te 4 is a superconducting topological metal 24 . Nontrivial topological properties, FM semiconductors, Ising superconductivity, and robust electron valleys are also found in SrGa 2 Te 4 , NbSi 2 N 4 , TiSi 2 N 4 , MoSi 2 P 4 , MoSi 2 As 4 , WSi 2 P 4 , and WSi 2 As 4 21,25 .…”