Superconducting $2H-\mathrm{NbS}{\mathrm{e}}_2$ single crystals show intrinsic low pinning values. Therefore, they are ideal materials with which to explore fundamental properties of vortices. ($V, I$) characteristics are the experimental data we have used to investigate the dissipation mechanisms in a rectangular-shaped $2H-\mathrm{NbS}{\mathrm{e}}_2$ single crystal. Particularly, we have studied dissipation behavior with magnetic fields applied in the plane of the crystal and parallel to the injected currents, i.e., in the force-free state where the vortex helical instability governs the vortex dynamics. In this regime, the data follow the elliptic critical state model and the voltage dissipation shows an exponential dependence, $V\propto e^{\alpha \left(I-I_{C\parallel }\right)}, I_{C\parallel }$ being the critical current in the force-free configuration and α a linear temperature-dependent parameter. Moreover, this exponential dependence can be observed for in-plane applied magnetic fields up to 40° off the current direction, which implies that the vortex helical instability plays a role in dissipation even out of the force-free configuration.

• Received 24 January 2017
• Revised 23 April 2017

DOI:https://doi.org/10.1103/PhysRevB.95.224510