The responses to the magnetic field (H) of the pseudogap and the superconductivity in the underdoped high-Tc cuprate YBa2Cu4O8 (Tc=74 K) are reported up to 23.2 T based on NMR measurements. Even though 23.2 T reduces Tc by 26%, no effect is seen on the normal-state pseudogap, which persists in the temperature range where the superconductivity is destroyed by the field. For temperatures T≤15 K, the spin Knight shift increases with increasing H and also the H and T variation of the 63Cu nuclear spin-lattice relaxation rate (1/T1) is 1/T1∝TH. A possible explanation for this finding is offered as due to the H-induced quasiparticle states that extend from the d-wave vortex centers with ungapped spectrum.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 1999|
ASJC Scopus subject areas
- Condensed Matter Physics