Site-selective $^{63}$Cu NMR study of the vortex cores of Tl$_{2}$Ba$_{2}$CuO$_{6+\delta}$

Abstract

We report site-selective $^{63}$Cu NMR studies of the vortex core states of an overdoped Tl$_{2}$Ba$_{2}$CuO$_{6+\delta}$ with $T_{c}$ = 85 K. We observed a relatively high density of low-energy quasi-particle excitations at the vortex cores in a magnetic field of 7.4847 T along the c axis, in contrast to YBa$_{2}$Cu$_{3}$O$_{7-\delta}$.