A. S. Dormidontov | Searcharxiv

arXiv2011

Observation of Multi-Gap Superconductivity in GdO(F)FeAs by Andreev Spectroscopy

We have studied current-voltage characteristics of Andreev contacts in polycrystalline GdO$_{0.88}$F$_{0.12}$FeAs samples with bulk critical temperature ${T_c}$ = (52.5 \pm 1)K using break-junction technique. The data obtained cannot be described within the single-gap approach and suggests the existence of a multi-gap superconductivity in this compound. The large and small superconducting gap values estimated at T = 4.2K are ΔL = 10.5 \pm 2 meV and ΔS = 2.3 \pm 0.4 meV, respectively.

cond-mat.supr-con↗

arXiv2006

Charge Transport in a Spin-Polarized 2D Electron System in Silicon

The temperature dependences of the conductivity σ(T) for strongly interacting 2D electron system in silicon have been analyzed both in zero magnetic field and in spin-polarizing magnetic field of 14.2T, parallel to the sample plane. Measurements were carried out in a wide temperature range (1.4-9)K, in the ballistic regime of electron-electron interaction, i.e., for Tτ> 1. In zero magnetic field, the data obtained for σ(T) are quantitatively described by the theory of interaction corrections. In the fully spin-polarized state, the measured σ(T) dependences are nonlinear and even nonmonotonic for the same temperature range, where the σ(T) dependences are monotonic in the absence of the field. Nevertheless, the low-temperature parts of the experimental σ(T) dependences are linear and are qualitatively consistent with the calculated interaction corrections.

cond-mat.str-el↗