Bound states 2023

Superconductor-semiconductor hybrid devices for quantum science and technology

R. Seoane Souto

Division of Solid State Physics and NanoLund, Lund University, S-221 00 Lund, Sweden
Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
Departamento de Física Teórica de la Materia Condensada, Condensed Matter Physics Center (IFIMAC) and Instituto Nicoláss Cabrera, Universidad Autónoma de Madrid E-28049 Madrid, Spain

When a semiconductor is brought into proximity with a superconductor, superconductivity can leak into the semiconductor (superconducting proximity effect). The resulting superconducting state can inherit several interesting properties from the semiconductor, such as large g-factors, strong spin-orbit coupling and the ability to tune the density of Cooper pairs with a gate voltage. In my presentation, I will discuss how to engineer these properties by choosing appropriate superconducting and semiconducting materials, and by controlling the geometry of the hybrid structures. I will also discuss how to exploit the properties of superconductor-semiconductor hybrid structures in new types of superconducting circuits and quantum devices, including qubits. A particular focus has been on reaching a topological superconducting phase, where Majorana bound states occur at edges and defects. I will discuss the prospect of reaching a topological superconducting phase in systems with proximity-induced magnetism [1 – 3], as well as in chains of strongly interacting quantum dots [4 – 6].

[1] A. Maiani, et al., Physical Review B 103, 104508 (2021)
[2] S. Vaitiekėnas, et al., Phys. Rev. B 105, L041304 (2022)
[3] S. D. Escribano, et al., npj Quantum Materials 7, 81 (2022)
[4] M. Leijnse and K. Flensberg, Phys. Rev. B 86, 134528 (2012)
[5] T. Dvir et al., arXiv:2206.08045 (2022)
[6] A. Tsintzis, R. Seoane Souto, and M. Leijnse, Phys. Rev. B 106, L201404 (2022)