Abstract
Although magnetism and superconductivity hardly coexist in a single material, recent advances in nanotechnology and spintronics have brought to light their interplay in magnetotransport in thin-film heterostructures. Here, we found a periodic oscillation of Nernst voltage with respect to magnetic fields in Pt|LiFe5O8 (Pt|LFO) bilayers grown on a cuprate superconductor YBa2Cu3O7−x (YBCO). At high temperatures above the superconducting transition temperature (TC) of YBCO, spin Seebeck voltages originating in Pt|LFO layers are observed. As temperature decreases well below TC, the spin Seebeck voltage is suppressed and unconventional periodic voltage oscillation as a function of magnetic fields appears; such an oscillation emerging along the Hall direction in the superconducting state has not been observed yet. Dynamics of superconducting vortices pinned by surface precipitates seems responsible for the oscillatory Nernst effect.
Highlights
Transport effects in ferromagnet|superconductor hybrid structures have attracted considerable interest recently
In ferromagnet|superconductor hybrid structures, thermoelectric effects are expected to lead to improved devices similar to normal-state spin caloritronics
When a heat current is applied to a vortex system, flux lines start to move along the direction of the temperature gradient and generate electromotive force in the Hall direction, known as the vortex Nernst effect[15,16,17]
Summary
Magnetism and superconductivity hardly coexist in a single material, recent advances in nanotechnology and spintronics have brought to light their interplay in magnetotransport in thin-film heterostructures. In s-wave and d-wave superconductors, the Cooper pair resides in a spin-singlet state, and the coupling of spin and charge transport is usually weak[1]. Both superconductivity and spin polarization can unite under the right conditions at ferromagnet|superconductor interfaces. In ferromagnet|superconductor hybrid structures, thermoelectric effects are expected to lead to improved devices similar to normal-state spin caloritronics. Thermoelectric effects in ferromagnet|superconductor hybrids have mainly focused on the transport of Cooper pairs and quasiparticles[10,11,12,13].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
