SPICE Workshop on Quantum Matter for Quantum Technologies, May 21st - May 23rd 2024
Szabolcs Csonka
Topological superconductivity provides a promising platform to realize fault tolerant quantum hardware. The simplest topological superconducting system is the Kitaev-model which is a chain of localized sites where neighboring ones are coupled by superconducting pairing and direct tunneling. Since state-of-the-art semiconducting nanostructures allows to create artificial atoms and tunnel couple them or interconnect by superconductors, the basic ingredients are available to build up artificial chains, which we call superconducting artificial molecule, or Andreev-molecule. Very recently various realizations of such chains have been reported where the sites are coupled in different ways, e.g. via superconducting vacuum, superconducting bound state, or superconducting artificial atom.
We will present experimental realization of two types of Andreev-molecule: i) the analog of H_2 molecule, where two artificial atoms are tunnel coupled via a superconducting vacuum [1] and ii) the analog of H_20 molecule, where two artificial atoms are coupled via a 3rd superconducting atom [2].
[1] O. Kürtössy et al., Nano Letters, 21, 7929 (2021). [2] O. Kürtössy et al., under preparation (2024).