Deterministic phase slips in mesoscopic superconducting rings
نویسندگان
چکیده
The properties of one-dimensional superconductors are strongly influenced by topological fluctuations of the order parameter, known as phase slips, which cause the decay of persistent current in superconducting rings and the appearance of resistance in superconducting wires. Despite extensive work, quantitative studies of phase slips have been limited by uncertainty regarding the order parameter's free-energy landscape. Here we show detailed agreement between measurements of the persistent current in isolated flux-biased rings and Ginzburg-Landau theory over a wide range of temperature, magnetic field and ring size; this agreement provides a quantitative picture of the free-energy landscape. We also demonstrate that phase slips occur deterministically as the barrier separating two competing order parameter configurations vanishes. These results will enable studies of quantum and thermal phase slips in a well-characterized system and will provide access to outstanding questions regarding the nature of one-dimensional superconductivity.
منابع مشابه
Vortex Matter in Mesoscopic Superconducting Disks and Rings
Phase transitions between different (i.e. giant and multi-vortex) superconducting states and between the superconducting-normal state of mesoscopic disks and rings are studied in the presence of an external magnetic field by solving the two non-linear Ginzburg-Landau equations self-consistently. The flux through a circular disk with a hole in the middle is not quantized.
متن کاملFluxoid fluctuations in mesoscopic superconducting rings
Superconducting rings represent an ideal system for studying phase coherence in one dimension. We study the temperature dependence of the magnetic susceptibility of superconducting rings with a scanning superconducting quantum interference device. The physical parameters of the rings were designed to reduce the superconducting phase stiffness. We observe a suppression of the susceptibility sign...
متن کاملSignatures of topological phase transitions in mesoscopic superconducting rings
We investigate Josephson currents in mesoscopic rings with a weak link which are in or near a topological superconducting phase. As a paradigmatic example, we consider the Kitaev model of a spinless p-wave superconductor in one dimension, emphasizing how this model emerges frommore realistic settings based on semiconductor nanowires. We show that the flux periodicity of the Josephson current pr...
متن کاملPhoton-induced Entanglement of Distant Mesoscopic Squid Rings
An experiment that involves two distant mesoscopic SQUID rings is studied. The superconducting rings are irradiated with correlated photons, which are produced by a single microwave source. Classically correlated (separable) and quantum mechanically correlated (entangled) microwaves are considered, and their effect on the Josephson currents is quantified. It is shown that the currents tunnellin...
متن کاملCoherent Current States in Mesoscopic Four-terminal Josephson Junction
A theory is offered for the ballistic 4-terminal Josephson junction. The studied system consists of a mesoscopic two-dimensional normal rectangular layer which is attached in each side to the bulk superconducting banks (terminals). The relation between the currents through the different terminals, which is valid for arbitrary temperatures and junction sizes, is obtained. The nonlocal coupling o...
متن کامل