Presentation Information
[PC3-01]Dimensional crossover of in-plane vortex state in a 2H-NbSe2 single crystalline flake
*Tsutomu Nojima1, Hirotaka Shirai1 (1. Institute for Materials Research, Tohoku University (Japan))
Keywords:
Transition metal dichalcogenide,upper critical field,Josephson vortex
We report on the superconducting state in the multilayer 2H-NbSe2 single crystalline flake (thickness of 80 nm), showing the upturn in temperature dependence of in-plane upper critical field Bc2(T) together with the extremely sharp cusp in angular dependence of Bc2. These anomalies have attracted much attention recently as a manifestation of exotic superconducting state such as the orbital FFLO state. In this work, we performed the transport measurement as a function of temperature, field, and out-of-plane θ and in-plane φ field directions, focusing on the motion of in-plane vortices across the superconducting layers. By using the special technique to pick up only the dynamics of in-plane dynamics of in-plane vortices, based on the simultaneous measurements of diagonal and off-diagonal resistance, Rxx and Ryx, at φ = ±45º, we found that the motion of in-plane vortices is suddenly suppressed in the narrow range of θ where the cusp in Bc2 (θ) appears. Our results indicate that the anomalies in Bc2// (T) and Bc2 (θ) appear as a consequence of dimensional crossover from the Abrikosov vortex state to Josephson vortex state. We will discuss the relevance of the results to previously predicted mechanisms for the anomalies in the critical field in multilayer transition metal dichalcogenides.