Searcharxiv⌕ Search

arXiv · cond-mat/0105342

Pulse-induced switches in a Josephson tunnel stacked device

Abstract

Pulse activated transitions from the metastable to the running state and viceversa have been observed in a stacked double tunnel Nb-based Josephson system. Experimental results are compared with numerical simulations based on the Sine-Gordon model of the stacked junctions by injecting pulses with variable amplitude in one of the junctions of the stack, and observing the voltage response of the other junction. Both experimental and numerical results show the possibility to induce both direct and back-switching transitions from the metastable to the running state simply by changing the amplitude of the electronic pulses injected across the stack device.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

G. P. Pepe, G. Peluso, M. Valentino, A. Barone, L. Parlato, E. Esposito, C. Granata, M. Russo, C. De Leo, G. Rotoli. 2001-05-17. Pulse-induced switches in a Josephson tunnel stacked device. https://doi.org/10.1063/1.1402652

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Same-spin correlation screens the exchange peak of the electron gas near 2kF

Exchange alone gives the electron gas a local field factor with a sharp peak just below 2kF. Quantum Monte Carlo finds none. Both spin channels are computed here from their lowest diagrams with a dynamically screened interaction and no fitting. Parallel spin correlation is the negative image of exchange and removes about half the peak; the calculated spin-resolved factors account for the QMC data at rs = 1 and 2, and at q = 0 for the compressibility and spin susceptibility obtained from the ground-state energy. The two classes of diagrams are the two terms of the kernel of Hedin's vertex equation, of which the second is routinely dropped.

cond-mat.supr-con↗

Local Josephson response near nonmagnetic impurities and vortices in a two-orbital $s_{\pm}$ superconductor

We study the local Josephson response near nonmagnetic impurities and vortices in a self-consistent two-orbital $s_{\pm}$ superconductor. For a local $s$-wave tip that couples equally to the two orbitals, anomalous spectral contributions of opposite sign nearly cancel in the clean sample. Nonmagnetic impurities redistribute these contributions and can reverse the local coupling without a corresponding $π$ phase shift of the bond pair fields. Negative coupling appears at off-center sites at weaker impurity potentials than at the impurity site. The impurity-induced change is concentrated at lower quasiparticle energies, while states over a broader energy range contribute to the total clean and impurity couplings. In zero field, the coupling also changes sign as the tip gap is varied, and increasing the tunneling strength can reverse the $m=1$ sine component of the current without changing the sample state. At the chosen coherence-peak energy, increasing impurity strength mainly changes the relative intensities of existing quasiparticle-interference features. In a self-consistent two-vortex state, the Josephson response develops a spatially varying phase relative to the condensate. The response and condensate share the winding close to each core, while larger loops enclose additional winding of the Josephson response. The local Josephson sign and phase reflect the anomalous spectrum and the tip--sample coupling.

cond-mat.supr-con↗

Thermalization-Controlled Superconducting Diode-Like Transport in Disordered Molybdenum and NbN Thin Films

Superconducting diode effects are characterized by direction-dependent critical currents in the superconducting state. Here, we investigate diode-like transport in 128-nm-thick Mo thin film deposited on Si_SiO2 substrate by DC magnetron sputtering. The thin film exhibit a superconducting transition temperature TC of 5.8 K. Pronounced current-direction asymmetry and hysteresis are observed in current-voltage characteristics measured in a closed-cycle refrigerator. In contrast, the same thin film exhibits a substantially more symmetric response in a 14T cryogenic system with improved sample thermalization. We attribute this strong dependence on the measurement environment to electrothermal effects arising from current-induced Joule heating and finite thermal relaxation. As the current approaches the superconducting-to-resistive switching condition, the emergence of a resistive component leads to a rapid increase in Joule heating, raising the sample temperature and modifying the switching condition. Conversely, during the resistive-to-superconducting transition, residual heating and finite thermal relaxation reduce the switching current. Since P is equal to I2R it is independent of current polarity, the observed asymmetry is not associated with polarity-dependent Joule heating but with the interplay of thermal relaxation, sweep history, and thermal boundary conditions. The suppression of the asymmetry under improved thermalization, together with similar behavior observed in NbN reference films, indicates that the apparent diode-like response is strongly influenced by electrothermal effects. These results highlight the need to distinguish thermal switching and hysteresis from intrinsic nonreciprocal superconductivity when identifying superconducting diode effects in transport measurements.

cond-mat.supr-con↗