Local Thermometry of NbSe2 Flake with Delta-T Noise Measurements

Abstract

We perform transport and noise measurements for device consisting of a thin NbSe₂ flake laid onto the predefined gold electrodes and covered with a thin hBN flake. In the shot noise of a NbSe₂/Au tunnel junction, we identify Andreev reflection regime by demonstrating the effective charge doubling. Further, by creating temperature gradient across the tunnel junction and measuring its delta-\(T\) noise in the normal state, we extract electron–phonon scattering length in NbSe₂ and its T-dependence. The results of delta-\(T\) noise measurements in the absence of a magnetic field when the flake is superconducting are in qualitative agreement with expectations. The introduced approach is promising for the study of nonequilibrium configurations in superconductors.