Spectral properties of fractionalized Shiba states

Abstract

A magnetic impurity in a BCS superconductor induces the formation of a Shiba state and drives a local quantum phase transition. We generalize this concept to a one-dimensional superconductor with fractionalized excitations, where the dominant instability is superconducting. In this framework, conduction electrons fractionalize into gapless charge and gapped spin excitations. We show that magnetic impurity interacts exclusively with the spin degrees of freedom and induces a quantum phase transition. Furthermore, charge excitations influence dynamical observables, giving rise to the phenomenon we term the fractionalized Shiba state. At zero temperature, the tunneling spectrum exhibits universal power-law scaling with an exponent of $-1/2$ at half filling, stemming from the gapless charge modes that form a standard Luttinger liquid. Extending this analysis to finite temperatures reveals that the spectral features retain universal behavior at the critical point.

6 pages, 4 figures

References in corpus (12)

• The density-matrix renormalization group in the age of matrix product states
• The Kernel Polynomial Method
• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Bosonizing one-dimensional cold atomic gases
• Observation of two-orbital spin-exchange interactions with ultracold SU(N)-symmetric fermions
• Transmission of topological surface states through surface barriers
• Spectral properties of locally correlated electrons in a BCS superconductor
• Chebyshev matrix product state approach for spectral functions
• Electron Cotunneling into a Kondo Lattice
• Chebyshev Matrix Product State Impurity Solver for the Dynamical Mean-Field Theory
• Tunneling processes between Yu-Shiba-Rusinov bound states
• Rise and fall of Yu-Shiba-Rusinov bound-states in charge conserving $s$-wave one-dimensional superconductors

Cited by in corpus (1)

• Tunneling spectroscopy of the spinon-Kondo effect in one-dimensional Mott insulators