|
|
Ovchinnikov YN, Varlamov AA. Fluctuation-dissipative phenomena in a narrow superconducting channel carrying current below critical. arXiv. 2009;0910.2659v1:1–4.
Abstract: The theory of current transport in a narrow superconducting channel accounting for thermal fluctuations is developed. These fluctuations result in the appearance of small but finite dissipation in the sample. The value of corresponding voltage is found as the function of temperature (close to transition temperature) and arbitrary bias current. It is demonstrated that the value of the activation energy (exponential factor in the Arrenius law) when current approaches to the critical one is proportional to (1-J/Jc)^(5/4). This result is in concordance with the one for the affine phenomenon of the Josephson current decay due to the thermal phase fluctuations, where the activation energy proportional (1-J/J_c)^(3/2)(the difference in the exponents is related to the additional current dependence of the order parameter). Found dependence of the activation energy on current explains the enormous discrepancy between the theoretically predicted before and the experimentally observed broadening of the resistive transition.
|
|
|
|
Korneeva Y, Florya I, Vdovichev S, Moshkova M, Simonov N, Kaurova N, et al. Comparison of hot-spot formation in NbN and MoN thin superconducting films after photon absorption. In: IEEE Transactions on Applied Superconductivity. Vol 27.; 2017. 5.
Abstract: In superconducting single-photon detectors SSPD
the efficiency of local suppression of superconductivity and hotspot
formation is controlled by diffusivity and electron-phonon
interaction time. Here we selected a material, 3.6-nm-thick MoNx
film, which features diffusivity close to those of NbN traditionally
used for SSPD fabrication, but with electron-phonon interaction
time an order of magnitude larger. In MoNx detectors we study
the dependence of detection efficiency on bias current, photon
energy, and strip width and compare it with NbN SSPD. We
observe non-linear current-energy dependence in MoNx SSPD
and more pronounced plateaus in dependences of detection
efficiency on bias current which we attribute to longer electronphonon
interaction time.
|
|
|
|
Anthore A, Pothier H, Esteve D. Density of states in a superconductor carrying a supercurrent. Phys Rev Lett. 2003;90(12):127001 (1 to 4).
Abstract: We have measured the tunneling density of states (DOS) in a superconductor carrying a supercurrent or exposed to an external magnetic field. The pair correlations are weakened by the supercurrent, leading to a modification of the DOS and to a reduction of the gap. As predicted by the theory of superconductivity in diffusive metals, we find that this effect is similar to that of an external magnetic field.
|
|
|
|
Pothier H, Guéron S, Birge NO, Esteve D, Devoret MH. Energy distribution function of quasiparticles in mesoscopic wires. Phys. Rev. Lett.. 1997;79(18):3490–3.
Abstract: We have measured with a tunnel probe the energy distribution function of Landau quasiparticles in metallic diffusive wires connected to two reservoir electrodes, with an applied bias voltage. The distribution function in the middle of a 1.5-μm-long wire resembles the half sum of the Fermi distributions of the reservoirs. The distribution functions in 5-μm-long wires are more rounded, due to interactions between quasiparticles during the longer diffusion time across the wire. From the scaling of the data with the bias voltage, we find that the scattering rate between two quasiparticles varies as <c9><203a>–2, where <c9><203a> is the energy transferred.
|
|
|
|
Shah N, Pekker D, Goldbart PM. Inherent stochasticity of superconductor-resistor switching behavior in nanowires. Phys Rev Lett. 2008;101:207001(1 to 4).
Abstract: We study the stochastic dynamics of superconductive-resistive switching in hysteretic current-biased superconducting nanowires undergoing phase-slip fluctuations. We evaluate the mean switching time using the master-equation formalism, and hence obtain the distribution of switching currents. We find that as the temperature is reduced this distribution initially broadens; only at lower temperatures does it show the narrowing with cooling naively expected for phase slips that are thermally activated. We also find that although several phase-slip events are generally necessary to induce switching, there is an experimentally accessible regime of temperatures and currents for which just one single phase-slip event is sufficient to induce switching, via the local heating it causes.
|
|
