Existence of low-lying electron spin excitations in the superconducting state of the Tl2Ba2CuO6+x system
Vyaselev O. M., Kolesnikov N. N., Shchegolev I. F.
The rate of spin-lattice relaxation of Tl has been measured for TI2Ba2Cu06+x samples with Tc=30 and 100 К in fields from 0.5 to 7 T. At Tc<60-70 К this rate increases with decreasing field. In a sample with Гс = 30 К this increase is observed even in the normal state, so fluctuations of vortices can be ruled out as a possible reason for this increase. It has been established previously that the spin component of the Knight shift is independent of the field and exhibits a gap behavior at T<TC. These facts indicate that the mechanism for the nuclear relaxation probably involves antiferromagnetic fluctuations of electron spins, which persist below the transition temperature in the Tl2Ba2Cu06+jr system. © 1994 American Institute of Physics.