Discrete vortex bound states with a van Hove singularity in the vicinity of the Fermi level

A theoretical study on discrete vortex bound states is carried out near a vortex core in the presence of a van Hove singularity (VHS) near the Fermi level by solving Bogoliubov-de Gennes (BdG) equations. When the VHS lies exactly at the Fermi level and also at the middle of the band, a zero-energy state and other higher-energy states whose energy ratios follow integer numbers emerge. These discrete vortex bound state peaks undergo a splitting behavior when the VHS or Fermi level moves away from the middle of the band. Such splitting behavior will eventually lead to a new arrangement of quantized vortex core states whose energy ratios follow half-odd-integer numbers.

Automated summary

A theoretical study was conducted on discrete vortex bound states near a vortex core in the presence of a van Hove singularity (VHS) near the Fermi level using the Bogoliubov-de Gennes (BdG) equations. When the VHS is exactly at the Fermi level and in the middle of the band, a zero-energy state and higher-energy states with energy ratios following integer numbers emerge. These discrete vortex bound state peaks undergo splitting behavior when the VHS or Fermi level moves away from the middle of the band, eventually leading to a rearrangement of quantized vortex core states with energy ratios following half-odd-integer numbers.