Fast vortex dynamics and relaxation times in NbRe-based heterostructures

• Francesco De Chiara,
• Zahra Makhdoumi Kakhaki,
• Francesco Avitabile,
• Francesco Colangelo,
• Abhishek Kumar,
• Carmine Attanasio and
• Carla Cirillo

Beilstein J. Nanotechnol. 2026, 17, 292–302, doi:10.3762/bjnano.17.20

• , were characterized through electrical transport measurements. The I–V characteristics show that, in the NbRe/Py bilayer, vortices reach higher critical velocities than those observed in the NbRe/Au structure. The analysis of the flux-flow instability within the Larkin–Ovchinnikov framework allows one

• bilayers, having a relaxation time one order of magnitude smaller than values reported in NbRe microbridges, have great potential for the realization of devices where fast relaxation processes are required. Keywords: flux-flow instability; quasiparticle relaxation time; superconducting heterostructures

• superconducting coherence. This phenomenon, known as flux-flow instability (FFI), depends on several factors such as structural disorder and defects [3], pinning mechanisms [4][5], thermal effects [6], and sample geometry [7]. FFI is effectively described by the Larkin–Ovchinnikov (LO) model [8], which relates