Shifts of the nuclear resonance in the vortex lattice in YBa$_2$Cu$_3$O$_7$

TL;DR

This paper explains the shifts in nuclear resonance observed in the vortex lattice of YBa₂Cu₃O₇ using an extended Ginzburg-Landau theory and the Bernoulli potential, accounting for charge transfer effects.

Contribution

It applies a phenomenological Ginzburg-Landau extension to interpret NMR/NQR spectra in the superconducting state of YBa₂Cu₃O₇, incorporating charge transfer between planes and chains.

Findings

Spectra explained by Bernoulli potential theory.

Charge transfer between CuO₂ planes and chains is significant.

Standard theory accounts for observed resonance shifts.

Abstract

The NMR and NQR spectra of $^{63}$Cu in the CuO$_2$ plane of YBa$_2$Cu$_3$O$_7$ in the superconducting state are discussed in terms of the phenomenological theory of Ginzburg-Landau type extended to lower temperatures. We show that the observed spectra, Kumagai {\em et al.}, PRB {\bf 63}, 144502 (2001), can be explained by a standard theory of the Bernoulli potential with the charge transfer between CuO$_2$ planes and CuO chains assumed.