TY - JOUR
T1 - Delocalized Quasiparticles in the Vortex State of an Overdoped High- [Formula presented] Superconductor Probed by [Formula presented] NMR
AU - Zheng, G. q.
AU - Ozaki, H.
AU - Kitaoka, Y.
AU - Kuhns, P.
AU - Reyes, A. P.
AU - Moulton, W. G.
PY - 2002
Y1 - 2002
N2 - We report the spin Knight shift ([Formula presented]) and the nuclear spin-lattice relaxation rate ([Formula presented]) in the vortex state as a function of magnetic field ([Formula presented]) up to 28 T in the high- [Formula presented] superconductor [Formula presented] ([Formula presented]). At low temperatures well below [Formula presented], both [Formula presented] and [Formula presented] measured around the middle point between the two nearest vortices (saddle point) increase substantially with increasing field, which indicate that the quasiparticle states with an ungapped spectrum are extended outside the vortex cores in a [Formula presented]-wave superconductor. The density of states (DOS) around the saddle point is found to be [Formula presented], with [Formula presented] and [Formula presented] being the normal-state DOS.
AB - We report the spin Knight shift ([Formula presented]) and the nuclear spin-lattice relaxation rate ([Formula presented]) in the vortex state as a function of magnetic field ([Formula presented]) up to 28 T in the high- [Formula presented] superconductor [Formula presented] ([Formula presented]). At low temperatures well below [Formula presented], both [Formula presented] and [Formula presented] measured around the middle point between the two nearest vortices (saddle point) increase substantially with increasing field, which indicate that the quasiparticle states with an ungapped spectrum are extended outside the vortex cores in a [Formula presented]-wave superconductor. The density of states (DOS) around the saddle point is found to be [Formula presented], with [Formula presented] and [Formula presented] being the normal-state DOS.
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U2 - 10.1103/PhysRevLett.88.077003
DO - 10.1103/PhysRevLett.88.077003
M3 - Article
AN - SCOPUS:77950369865
SN - 0031-9007
VL - 88
SP - 4
JO - Physical Review Letters
JF - Physical Review Letters
IS - 7
ER -