Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1101.0817

Cratered Lorentzian response of driven microwave superconducting nanowire-bridged resonators: oscillatory and magnetic-field induced stochastic states

Matthew W. Brenner·Sarang Gopalakrishnan·Jaseung Ku·Timothy J. McArdle·James N. Eckstein·Nayana Shah·Paul M. Goldbart·Alexey Bezryadin
View original source ↗Read source document ↗Export metadata ↓

Abstract

Microwave Fabry-Perot resonators containing nonlinear mesoscopic elements (such as superconducting nanowires) can be used to explore many-body circuit QED. Here, we report on observations of a superconductor-normal pulsing regime in microwave (GHz) coplanar waveguide resonators consisting of superconducting MoGe films interrupted by a gap that is bridged by one or more suspended superconducting nanowires. This regime, which involve MHz-frequency oscillations in the amplitude of the supercurrent in the resonator, are achieved when the steady-state amplitude of the current in the driven resonator exceeds the critical current of the nanowires. Thus we are able to determine the temperature dependence of the critical current, which agrees well with the corresponding Bardeen formula. The pulsing regime manifests itself as an apparent "crater" on top of the fundamental Lorentzian peak of the resonator. Once the pulsing regime is achieved at a fixed drive power, however, it remains stable for a range of drive frequencies corresponding to subcritical steady state currents in the resonator. We develop a phenomenological model of resonator-nanowire systems, from which we are able to obtain a quantitative description of the amplitude oscillations and also, inter alia, to investigate thermal relaxation processes in superconducting nanowires. For the case of resonators comprising two parallel nanowires and subject to an external magnetic field, we find field-driven oscillations of the onset power for the amplitude oscillations, as well as the occurrence (for values of the magnetic field that strongly frustrate the nanowires) of a distinct steady state in which the pulsing is replaced by stochastic amplitude-fluctuations. We conclude by giving a brief discussion of how circuit-QED-based systems have the potential to facilitate understanding of quantum phase-slips in superconducting nanowires.

Explore related subjects

cond-mat.supr-con

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Matthew W. Brenner, Sarang Gopalakrishnan, Jaseung Ku, Timothy J. McArdle, James N. Eckstein, Nayana Shah, Paul M. Goldbart, Alexey Bezryadin. 2011-01-04. Cratered Lorentzian response of driven microwave superconducting nanowire-bridged resonators: oscillatory and magnetic-field induced stochastic states. https://doi.org/10.1103/physrevb.83.184503

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

KEEP EXPLORING

Related papers

arXiv2026

Theoretical Prediction of Optimal $T_c$ and Fermi Pockets in Nickelate Superconductors

High-pressure bilayer $La_{3-x}Sm_{x}Ni_{2}O_{7-δ}$ (LSNO) reaches a record $T_c=96 K$, triggering wide discussion on the $T_c$ ceiling of nickelate superconductors. We show monoclinic and tetragonal LSNO share the same octahedral quantum-well motif governing $T_c$ with $YBa_{2}Cu_{3}O_{7-δ}$ (YBCO). Using the Planckian quantum-well scaling $T_c = Λ/ξ^{2}$ ($ξ$: lattice-modulated quantum-well depth), we obtain $T_c=93.4 K$ and $97.1 K$ for monoclinic and tetragonal LSNO, matching experimental values $92 K$ and $96 K$. Despite distinct stoichiometry and global symmetry ($P2_1/m$ for LSNO, $Pmmm$ for orthorhombic YBCO), both systems have nearly identical $ξ$ ($3.6629$ angstrom vs. $3.6720$ angstrom) and consistent $T_c$ responses. Further calculations yield a universal $T_c$ limit $\sim100 K$ for rare-earth nickelates, irrespective of stacking sequences. We examine four nickelate multilayer stacking variants: 2222 (pure bilayer), 1212 (alternating single-bilayer), 2323 (bilayer-trilayer), and 1313 (single-trilayer). Mirror symmetry breaking of coupled twin quantum wells, unique to bilayer nickelates, dictates $γ$ Fermi pocket formation and ambient-pressure superconductivity. We further prove Fermi surfaces constitute a hologram of quantum-well electrons, establishing intrinsic links between quantum-well symmetry breaking, Fermi pocket structural evolution, and superconducting properties.

cond-mat.supr-con↗
arXiv2026

Enhanced superconductivity in palladium hydrides by non-perturbative electron-phonon effects

Palladium hydrides exhibit the largest isotope-effect anomaly in superconductivity: replacing hydrogen with heavier isotopes increases the superconducting critical temperature. Although this behavior is commonly attributed to strong anharmonic hydrogen vibrations, \textit{ab initio} treatments have so far incorporated anharmonic effects only through phonon renormalization, neglecting non-linear contributions to the electron-phonon interaction vertices. While such approaches reproduce the anomalous isotope trend, they severely underestimate the critical temperatures. Here, we show that non-linear electron-phonon coupling is essential in palladium hydrides. A straightforward inclusion of higher-order perturbative terms leads to a qualitative breakdown: the critical temperature is overestimated and the isotope anomaly is lost. We therefore adopt a non-perturbative framework based on an explicit evaluation of the ion-mediated electron-electron interaction, enabling anharmonic effects to be treated consistently in both the phonon spectra and the interaction vertices. Applied to PdH and PdD, it restores the anomalous isotope effect and brings calculated critical temperatures into significantly improved agreement with experiments.

cond-mat.supr-con↗
arXiv2026

Optical manifestations of loop currents in Haldane's model and in time-reversal-breaking superconductors

We present a theoretical study of optical manifestations of loop currents in Haldane's model and in time-reversal-breaking superconductors. For Haldane's model, we calculate the expectation value of loop currents in terms of model parameters and relate it with the integrated optical spectral weight for the frequency-dependent ac Hall conductivity. Thus, experimental measurements of the latter can provide information about the presence and magnitude of steady loop currents in the system. Then we elaborate on loop currents in a chiral superconductor on the honeycomb lattice, studied earlier by Brydon et al. (2019). We demonstrate that a sharp optical absorption peak in the ac Hall conductivity originates from excitations between the lower and upper Dirac bands, activated by the time-reversal-breaking superconductivity. The frequency of the peak is twice the energy difference between the Fermi level and the Dirac point. The optical spectral weight of the peak is directly related to the magnitude of loop currents induced in the unit cells by the chiral superconducting pairing, in similarity to Haldane's model.

cond-mat.supr-con↗