# Quasiparticle excitation in and around the vortex core of underdoped YBa\_2Cu\_4O\_8 studied by site-selective NMR

Source: [Quasiparticle excitation in and around the vortex core of underdoped YBa\_2Cu\_4O\_8 studied by site-selective NMR](<https://www.sota2.com/research/paper/68fa254c2c2a3760193aed80>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-24T10:37:51.915Z

Authors: K. Kakuyanagi, K. Kumagai, Yuji Matsuda

Published: 2001-04-13T11:24:23.000Z

## Abstract

We report a site-selective ^{17}O spin-lattice relaxation rate T\_1^{-1} in the vortex state of underdoped YBa\_2Cu\_4O\_8. We found that T\_1^{-1} at the planar sites exhibits an unusual nonmonotonic NMR frequency dependence. In the region well outside the vortex core, T\_1^{-1} cannot be simply explained by the density of states of the Doppler-shifted quasiparticles in the d-wave superconductor. Based on T\_1^{-1} in the vortex core region, we establish strong evidence that the local density of states within the vortex core is strongly reduced.

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## Original sources and implementation

[Original paper](<https://arxiv.org/abs/cond-mat/0104252>)

[PDF](<https://arxiv.org/pdf/cond-mat/0104252.pdf>)