Local Electronic Structure of a Single Magnetic Impurity in a Superconductor

TL;DR

This paper investigates the local electronic structure around a single magnetic impurity in a superconductor using a self-consistent three-dimensional model, revealing new insights into impurity-induced states and their spatial characteristics.

Contribution

It presents the first self-consistent three-dimensional calculation of a strong magnetic impurity in a superconductor, showing distinct spatial structures of electron-like and hole-like states.

Findings

Localized in-gap states are identified as half electron and half hole.

The spatial structure of spectral weight differs significantly between positive and negative frequencies.

The effect on continuum states above the gap is characterized with high spectral resolution.

Abstract

The electronic structure near a single classical magnetic impurity in a superconductor is determined using a fully self-consistent Koster-Slater algorithm. Localized excited states are found within the energy gap which are half electron and half hole. Within a jellium model we find the new result that the spatial structure of the positive-frequency (electron-like) spectral weight (or local density of states), can differ strongly from that of the negative frequency (hole-like) spectral weight. The effect of the impurity on the continuum states above the energy gap is calculated with good spectral resolution for the first time. This is also the first three-dimensional self-consistent calculation for a strong magnetic impurity potential.