Chirality Detection through Vortex Bound States in ($d+id'$)-Wave Superconductor

• Main Authors: Yoshida, Soma, Tanaka, Yukio, Golubov, Alexander A, Suzuki, Shu-Ichiro
• Format: Journal Article
• Language: English
• Published: 11-09-2024
• Subjects: Physics - Superconductivity
• DOI: 10.48550/arxiv.2409.07711

We present a method for detecting the chirality $\chi$ of a ($d_{zx}+i \chi
d_{yz}$)-wave superconductor through the analysis of the local density of
states (LDOS) at the vortex core. Employing the quasiclassical Eilenberger
theory, we examine the LDOS in a semi-infinite superconductor with a quantum
vortex penetrating the surface perpendicularly. We show that
$\mathrm{sgn}[\chi]$ changes completely the LDOS at the core-surface
intersection. Remarkably, the difference between LDOS for the $\chi = 1$ and
$\chi = -1$ states becomes more prominent when the surface is dirtier, meaning
that one does not need to pay close attention to the surface quality of the
sample. The difference between these two states arises from the symmetry of the
subdominant Cooper pairs induced at the core-surface intersection: whether the
subdominant $s$-wave Cooper pairs are present or not. Due to the unique nature
of this phenomenon in the ($d_{zx}+i \chi d_{yz}$)-wave superconductor, one can
potentially demonstrate the realization of the ($d_{zx}+i \chi d_{yz}$)-wave
superconductivity and determine its chirality by, for instance, through
scanning tunnel spectroscopy experiments.