Materials for Quantum Computing

Quantum computing is emerging as the next digital revolution. In solid-state implementations computing errors ultimately originate from the materials comprising the quantum bits (qubits). Fault tolerant qubits may be encoded in exotic quantum states that exist in topological low dimensional systems. One of the most promising material systems for this purpose is hybrid superconductor/ semiconductor/ ferromagnet interfaces. The desired quantum computing functionality, or even the very existence of exotic topological quantum states, depend critically on the nature of the interface at the atomistic level. Epitaxial, atomically sharp, defect free interfaces are particularly desirable.

Our goal is to explore the materials space of hybrid superconductor/ semiconductor/ ferromagnet interfaces in the context of quantum computing. We aim to discover new material combinations for epitaxial interfaces, in which topological phases may exist, as well as metastable interface phases with desirable properties that may be stabilized by epitaxial templating. To this end, we employ a computational approach combining density functional theory (DFT) with lattice matching and genetic algorithm optimization. Lattice matching is used for screening a large number of candidate interfaces and genetic algorithms are used for detailed studies of the most promising candidates. This may guide the experiments of our collaborators in promising directions and advance the realization of new quantum computing schemes.