Enhancing the excitation gap of a quantum-dot-based Kitaev chain

Enhancing the excitation gap of a quantum-dot-based Kitaev chain

Blog Article

Abstract Connecting double quantum dots via a semiconductor-superconductor hybrid segment offers a platform for creating a two-site Kitaev chain that hosts Majorana zero modes at a finely tuned sweet spot.However, the effective couplings mediated by Andreev bound states in the hybrid are generally weak in the tunneling regime.As a neck cream consequence, the excitation gap is limited in size, presenting a formidable challenge for using this platform to demonstrate non-Abelian statistics and realize topological quantum computing.Here we systematically study the effects of increasing the dot-hybrid coupling.In particular, the proximity effect transforms the dot orbitals into Yu-Shiba-Rusinov states, and as the coupling strength increases, the excitation gap is significantly enhanced and sensitivity to local perturbation is reduced.

We also discuss how the strong-coupling regime shows in experimentally accessible quantities, such as conductance, and provide a protocol for tuning a double-dot system into a Ceramic Terminal Strip sweet spot with a large excitation gap.