Spin-sensitive interference due to Majorana state on the interface between normal and superconducting leads.

Area of Science:

• Condensed Matter Physics
• Quantum Information Science

Background:

• Topological superconductors host Majorana quasiparticles, exotic states with potential in quantum computing.
• Quantum dots coupled to superconducting leads provide a platform to study Majorana physics.

Purpose of the Study:

• Investigate the subgap spectrum and transport properties of a quantum dot side-coupled to a topological superconducting chain.
• Explore the spin-dependent effects of Majorana quasiparticles on quantum dot electrons.
• Determine if quantum interferometry can unambiguously identify Majorana quasiparticles.

Main Methods:

• Theoretical modeling of a quantum dot system interfaced with metallic and superconducting leads.
• Analysis of proximity-induced pairing and its influence on electron spins.
• Simulation of quantum interferometric patterns and their dependence on Majorana states and Kondo effect.

Main Results:

• Observed unique interferometric patterns distinct for each spin component due to Majorana quasiparticles.
• Demonstrated that proximity-induced pairing affects both spin components, despite chiral Majorana states.
• Showcased spin-sensitive interplay between Majorana quasiparticles and the Kondo effect at zero energy.

Conclusions:

• Quantum interferometry offers a robust method for unambiguous identification of Majorana quasiparticles.
• The interplay between Majorana states, Kondo effect, and quantum dot electron spins provides rich physics.
• This research advances the understanding of topological quantum matter and its potential applications.