The onset, evolution and magnetic braking of vortex lattice instabilities in nanostructured superconducting films

Abstract

In 1976 Larkin and Ovchinnikov [Sov. Phys. JETP 41, 960 (1976)] predicted that vortex matter in superconductors driven by an electrical current can undergo an abrupt dynamic transition from a flux-flow regime to a more dissipative state at sufficiently high vortex velocities. Typically this transition manifests itself as a large voltage jump at a particular current density, so-called instability current density $J^{\ast }$, which is smaller than the depairing current. By tuning the effective pinning strength in Al films, using an artificial periodic pinning array of triangular holes, we show that a unique and well defined instability current density exists if the pinning is strong, whereas a series of multiple voltage transitions appear in the relatively weaker pinning regime. This behavior is consistent with time-dependent Ginzburg-Landau simulations, where the multiple-step transition can be unambiguously attributed to the progressive development of vortex chains and subsequently phase-slip lines. In addition, we explore experimentally the magnetic braking effects, caused by a thick Cu layer deposited on top of the superconductor, on the instabilities and the vortex ratchet effect

References in corpus (6)

• Rearrangement of the vortex lattice due to instabilities of vortex flow
• Speed limit to the Abrikosov lattice in mesoscopic superconductors
• Vortex core deformation and stepper motor behavior in a superconducting ratchet
• Evidence of a new low field cross-over in the vortex critical velocity of type-II superconducting thin films
• Vortex instability in molybdenum-germanium superconducting films
• Classical analogy for the deflection of flux avalanches by a metallic layer

Cited by in corpus (7)

• Local flux-flow instability in superconducting films near Tc
• Supersonic dynamics of guided magnetic flux quanta
• Reversible ratchet effects in a narrow superconducting ring
• New scaling laws for pinning force density in superconductors
• A Robust nitridation technique for fabrication of disordered superconducting TiN thin films featuring phase slip events
• Fast Dynamics of Vortices in Superconductors
• Vortex rivers and multiple voltage transitions in superconducting MgB${}_2$ thin films