Coplanar Al/graphene/Al junctions fabricated onthe same graphene sheet deposited on silicon carbide (SiC), show robust Josephson coupling at subKelvin temperature, when the separations between the electrodes is below400 nm. Remarkably, a hysteretic Critical State sets in when ramping an orthogonal magnetic field, with a sudden collapseof the Josephson critical current Ic when turning thefield on, and a revival of Ic when inverting the sweep.Similar hysteresis can be found in granular superconducting films which may undergo the Berezinskii-Kosterlitz-Thouless transition. Here, we give quantitative argumentsto prove that this odd behavior of the magnetomeccanico gives evidence for an incipient Berezinskii-Kosterlitz-Thouless transition with drift and pinning of fluctuating freevortices induced by the current bias.
Hysteretic Critical State in Coplanar Josephson Junction with Monolayer Graphene Barrier
GIULIANO, Domenico;
2016-01-01
Abstract
Coplanar Al/graphene/Al junctions fabricated onthe same graphene sheet deposited on silicon carbide (SiC), show robust Josephson coupling at subKelvin temperature, when the separations between the electrodes is below400 nm. Remarkably, a hysteretic Critical State sets in when ramping an orthogonal magnetic field, with a sudden collapseof the Josephson critical current Ic when turning thefield on, and a revival of Ic when inverting the sweep.Similar hysteresis can be found in granular superconducting films which may undergo the Berezinskii-Kosterlitz-Thouless transition. Here, we give quantitative argumentsto prove that this odd behavior of the magnetomeccanico gives evidence for an incipient Berezinskii-Kosterlitz-Thouless transition with drift and pinning of fluctuating freevortices induced by the current bias.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
