Field dependence of NMR longitudinal relaxation rate 1/T₁ in single crystal of V₃Si down to milliKelvin temperatures

The A15 superconductor V₃Si, though the subject of nuclear magnetic resonance (NMR) studies for decades, continues to yield recent insights into its superconducting transition, as made possible by newer methods, the availability of a high-quality single-crystal sample, and access to temperatures down to the milliKelvin range. After finding evidence that the Martensitic transformation (MT) occurs over a range of temperatures in which transformed and untransformed phases coexist [Gapud et al., Physica C, vol. 602, 1354137], new data on the NMR longitudinal relaxation rate 1/T₁ has revealed interesting dependence on temperature and magnetic field across the superconducting transition and down to below 100 mK – including a possible smearing of quasiparticle states into the superconducting gap due to the incursion of vortices and an unexpected loss of temperature dependence close to 80 mK.