Does the nuclear spin relaxation rate in superconductors depend on disorder?

Nuclear spin relaxation rate of disordered px+ ipy-wave superconductors

Spin-wave contribution to the nuclear spin-lattice relaxation in triplet superconductors.

We discuss collective spin-wave excitations in triplet superconductors with an easy axis anisotropy for the order parameter. Using a microscopic model for interacting electrons, we estimate the frequency of such excitations in Bechgaard salts and ruthenate superconductors to be 1 and 20 GHz, respectively. We introduce an effective bosonic model to describe spin-wave excitations and calculate th...

Nuclear spin relaxation and Kondo disorder in UCu3.5Pd1.5

The Cu spin-lattice relaxation rate 1/T1 in UCu3.5Pd1.5 has been determined at frequencies 38 MHz<n0 <101 MHz and for temperatures 0.4 K<T<100 K. UCu3.5Pd1.5 was one of the first compounds revealing non-Fermi-liquid behavior which was explained in terms of a distribution of Kondo temperatures TK . In contrast to the broad distribution of single Kondo impurity temperatures TK , which accounted f...

Does Mutation Rate Depend on Itself?

M any a research paper, textbook chapter, and grant proposal has begun with the phrase " Mutation is the ultimate source of genetic variation. " Implicit in this phrase is the assumption that genetic variation is required for evolution. Without mutation, evolution would not be possible, and life itself could never have arisen in the first place. However, there is overwhelming evidence that the ...

Differential sum rule for the relaxation rate in dirty superconductors

We consider the differential sum rule for the effective scattering rate 1/t(v) and optical conductivity s1(v) in a dirty BCS superconductor, for arbitrary ratio of the superconducting gap D and the normal state constant damping rate 1/t . We show that if t is independent of T, the area under 1/t(v) does not change between the normal and the superconducting states, i.e., there exists an exact di...