Interplay Between Yu-Shiba-Rusinov States and Multiple Andreev Reflections

Abstract

Motivated by recent scanning tunneling microscopy experiments on single magnetic impurities on superconducting surfaces, we present here a comprehensive theoretical study of the interplay between Yu-Shiba-Rusinov bound states and (multiple) Andreev reflections. Our theory is based on a combination of an Anderson model with broken spin degeneracy and nonequilibrium Green's function techniques that allows us to describe the electronic transport through a magnetic impurity coupled to superconducting leads for arbitrary junction transparency. Using this combination we are able to elucidate the different tunneling processes that give a significant contribution to the subgap transport. In particular, we predict the occurrence of a large variety of Andreev reflections mediated by Yu-Shiba-Rusinov bound states that clearly differ from the standard Andreev processes in non-magnetic systems. Moreover, we provide concrete guidelines on how to experimentally identify the subgap features originating from these tunneling events. Overall, our work provides new insight into the role of the spin degree of freedom in Andreev transport physics.

15 pages, 10 figures

References in corpus (5)

• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• Orbital Picture of Yu-Shiba-Rusinov Multiplets
• Shiba states and zero-bias anomalies in the hybrid normal-superconductor Anderson model
• Scaling of Yu-Shiba-Rusinov energies in the weak-coupling Kondo regime
• The Andreev states of a superconducting quantum dot: mean field vs exact numerical results

Cited by in corpus (13)

• Proximity superconductivity in atom-by-atom crafted quantum dots
• Surrogate model solver for impurity-induced superconducting subgap states
• Tunneling processes between Yu-Shiba-Rusinov bound states
• Interplay between Majorana and Shiba states in a minimal Kitaev chain coupled to a superconductor
• Universal scaling of tunable Yu-Shiba-Rusinov states across the quantum phase transition
• Boosting the STM's spatial and energy resolution with double-functionalized probe tips
• Full Counting Statistics of Yu-Shiba-Rusinov Bound States
• Microwave Excitation of Atomic Scale Superconducting Bound States
• Control of Andreev Reflection via a Single-Molecule Orbital
• Characterizing local Majorana properties using Andreev states
• Temperature dependent energy gap for Yu-Shiba-Rusinov states at the quantum phase transition
• Diode effect in microwave irradiated Josephson junctions with Yu-Shiba-Rusinov states
• Yu-Shiba-Rusinov States in Ising Superconductors