Giant Shapiro Steps in a Superconducting Network of Nanoscale Nb Islands

Abstract

Recently, a dynamic vortex Mott transition has been observed in an array of superconducting nanodots. Here, we report the effect of the interaction of microwave radiation on this system and we show the occurrence of giant Shapiro steps.

Study of Energy Dissipation in the Mixed-State YBa2Cu3O7-δ Superconductor with Partially Deoxygenated Structures

“…Periodic pinning structures [6] control the phase of flux flow [5] or even the phase of coherent motion of vortices in comparatively wide superconducting devices, i.e., with a width larger than the effective penetration depth of the magnetic field. The latter can observe through a step-like I-V characteristic of the mixed-state superconductor, similar to those of the Shapiro steps observed in microwave-irradiated [7] and in the absence of microwave radiation [8] superconducting devices. The I-V characteristic then obtains a linear character, showing the FF resistivity, and steps appear at voltages at which the inverse of the vortex time of flight across a superconductor strip coincides with the frequency of vortex/antivortex nucleation at the edges of the superconducting device [9].…”

Superconductor-like effects in an AC driven normal Mott-insulating quantum dot array

“…However the sign of the diamagnetic response is anomalous (negative), equivalent to π-phase slips in the links, analogous to the η-pairing phase of Josephson arrays with negative phase stiffness. In the presence of a simultaneous DC bias, the DC IV characteristics exhibit Josephson-like photon-mediated tunneling in the form of current steps at bias values separated by integer multiples of hΩ/e (Ω being the drive frequency), but crucially, Shapiro steps -a key signature of Cooper pairs -expected at integer multiples of hΩ/2e are absent, unlike the observation in Josephson systems [26][27][28]. We propose that the similarities shared with η-pairing in Josephson systems do not imply AC induced superconductivity but are a manifestation of number-phase duality effects common to both.…”

A Novel Particle/Photon Detector Based on a Superconducting Proximity Array of Nanodots

“…The physics and the recent observation of a dynamic vortex Mott transition in a superconducting proximity array Nicola [1] together with the evidence of Shapiro steps measured at gigahertz [2] suggest the possibility to design a conceptually new particle/radiation detector. We propose here the layout and of a possible setup of a device.…”

“…A device based on a non-bolometric effect may lead to the detection even of a single photon, for example considering the radiation frequency in the internal Josephson oscillation range, i.e., from megahertz to gigahertz, up to the terahertz domain synchronization effects know as Shapiro steps occur. In this case we detect a jump of the current when the average voltage is an integer multiple of the AC frequency divided by the Josephson constant 2e/h = 483597011 GHz/V [1][2][3][4][5][6][7][8][9][10][11][12] Another non-bolometric device could be made with a "superconducting nanowire" 100 nm wide. This simple device may operate at a temperature well below the superconducting transition temperature of the corresponding film when the sample is biased just below the critical current.…”