Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:cond-mat/0603009 · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Calibration of quantum detector of noise based on a system of asymmetric superconducting loops

V. L. Gurtovoi, S. V. Dubonos, А. В. Никулов, N. N. Osipov, V. A. Tulin

Published May 24, 2006• 1 citation
arXivHTMLPDF

Abstract

The quantum oscillations V(Φ/Φ0) of the dc voltage are induced on segments of asymmetric superconducting loops by an external ac current or noise. The dependencies of the amplitude of V(Φ/Φ0) on amplitude of inducing ac current are measured at different temperatures below superconducting transition Tc on aluminum asymmetric loops and systems of the loops connected in series. The measured values of the maximum amplitude of the quantum oscillations V(Φ/Φ0), the amplitude of the ac current inducing this maximum dc voltage and the critical amplitude of the ac current decrease with temperature increase to Tc. The extrapolation of these measured dependencies to the region near superconducting transition allows to make a calibration of asymmetric superconducting loops as quantum detector of noise. The calibration restores an amplitude profile of the noise pulses from a measured temperature dependence of an amplitude of the quantum oscillations V(Φ/Φ0) induced by this noise. It is found that rectification efficiency, determined as relation of the maximum amplitude of the quantum oscillations V(Φ/Φ0) to the ac current amplitude inducing it, decreases near superconducting transition Tc. High efficiency of rectification observed below Tc is consequence of irreversibility of the current-voltage curves. Increase of the rectification efficiency is achieved in multiple series connected loop structures.

DOI
10.1117/12.681803

Related papers

Quantum detector of noise based on a system of asymmetric Al superconducting rings

Vladimir L. Gurtovoi, S. V. Dubonos, R. V. Kholin +3 more

The quantum rectification effect observed on asymmetric superconducting loops is proposed to use as a basic of a noise detector with maximum sensitivity. The measurements show that a critical amplitude of noise or ac current decreases down to zero near superconducting transition, Tc, just as superconducting critical current. Therefore any how weak noise, right down to the equilibrium one, can induce the quantum oscillations of the dc voltage near Tc. The transformation of the power of random noise into the dc power observed on asymmetric superconducting loops gives very important advantage: even very weak noise can give enough high output power in a system with large number of loops.

arXiv:cond-mat/0602655•Feb 28, 2006•0 citations

Multiple superconducting ring ratchets for ultrasensitive detection of non-equilibrium noises

V. L. Gurtovoi, M. Exarchos, V. N. Antonov +2 more

Magnetic quantum periodicity in the dc voltage is observed when asymmetric rings are switched between superconducting and normal state by a noise or ac current. This quantum effect is used for the detection of a non-equilibrium noise using a system of 667 asymmetric aluminum rings of 1 μm diameter connected in series. Any noise down to the equilibrium one can be detected with large number of asymmetric rings. The equilibrium noise can induce the dc voltage close to the superconducting transition. In our sample we observe the dc voltage oscillation only below the superconducting transition.

arXiv:1507.05957•Applied Physics Letters•Jul 18, 2016•10 citations

Rectified dc voltage versus magnetic field in a superconducting asymmetric figure-of-eight-shaped microstructure

В. И. Кузнецов, А. А. Firsov, S. V. Dubonos

We have measured periodic oscillations of rectified dc voltage versus magnetic field ${V}_{dc}(B)$ in a superconducting aluminum thin-film circular-asymmetric figure-of-eight microstructure threaded by a magnetic flux and biased with a sinusoidal alternating current (without a dc component) near the critical temperature. The Fourier spectra of these ${V}_{dc}(B)$ functions contain fundamental frequencies representing periodic responses of the larger and smaller asymmetric circular loops, composing the microstructure, to the magnetic field. The higher harmonics of the obtained fundamental frequencies result from the nonsinusoidal character of loop circulating currents. The presence of the difference and summation frequencies in these spectra points to the interaction between the quantum states of both loops. Magnitudes of the loop responses to the bias ac and magnetic field vary with temperature and the bias current amplitude, both in absolute values and with respect to each other. The strongest loop response appears when the average resistive state of the loop corresponds to the midpoint of the superconducting-normal phase transition.

arXiv:0710.5246•Physical Review B•Mar 31, 2008•7 citations

Asymmetry with respect to the magnetic field direction in the interaction between the quantum states of two coupled superconducting rings

В. И. Кузнецов, А. А. Firsov, S. V. Dubonos +1 more

The interaction between the quantum states of two circularly asymmetric superconducting aluminum rings forming figure eight, threaded by a magnetic flux and biased by an external sinusoidal ac current with zero dc component, has been investigated. Quantum oscillations in the dependence V dc(B) of the rectified dc voltage on magnetic field for these structures have been measured at different external currents and temperatures close to critical. Fourier and wavelet analyses of the function V dc(B) have revealed, along with the two fundamental ring frequencies, various combination frequencies; this fact is indicative of interaction in the structure. Deviation of the function V dc(B) from oddness with respect to the magnetic field direction has been found for the first time.

arXiv:0712.1602•Bulletin of the Russian Academy of Sciences Physics•Aug 1, 2007•2 citations

Asymmetric voltage noise in superconducting tunnel junctions with the electromagnetic environment

Martin Žonda, Tomáš Novotný

We investigate theoretically the V-I characteristics and voltage noise of superconducting tunnel junctions with small critical current via the matrix-continued-fraction method. Special attention is paid to the large hysteresis in the V-I characteristics and to the voltage-noise anomaly observed in preliminary experiments. The current dependence of the voltage noise shows a strong asymmetry between the forward and backward current ramping and a discontinuous change of the noise close to its measured maximum occurring at the switching current. We show that both the large hysteresis and the voltage noise anomaly in this current-biased setup are a consequence of the influence of junction's electromagnetic environment. Typically, the voltage-noise dependence on the junction current parametrized by the external drive contains a loop which is, however, not observed experimentally because of the implementation of the junction-current ramp. Skipping a part of the loop is responsible for the observed hysteresis as well as the noise anomaly.

arXiv:1212.0755•Physica Scripta•Nov 1, 2012•3 citations

Noise rectification by a superconducting loop with two weak links

Jorge Berger

We consider a superconducting loop with two weak links that encloses a magnetic flux. The weak links are unequal and are treated as Josephson junctions with non-sinusoidal phase dependence. We devise a model that takes into account the fluctuation of the critical currents, due to the fluctuations of the order parameter in the weak links. These fluctuations are important near the onset of superconductivity; in this regime they may significantly weaken and eventually disconnect the superconducting loop. As a consequence of these fluctuations and of the resistive noise in the junctions, the average dc voltage does not vanish. Our model can be easily extended to provide a qualitative description of a recent experiment.

arXiv:cond-mat/0305130•Physical Review B•Jul 30, 2004•18 citations
The quantum oscillations V(Φ/Φ0) of the dc voltage are induced on segments of asymmetric superconducting loops by an external ac current or noise. The dependencies of the amplitude of V(Φ/Φ0) on amplitude of inducing ac current are measured at different temperatures below superconducting transition Tc on aluminum asymmetric loops and systems of the loops connected in series. The measured values of the maximum amplitude of the quantum oscillations V(Φ/Φ0), the amplitude of the ac current inducing this maximum dc voltage and the critical amplitude of the ac current decrease with temperature increase to Tc. The extrapolation of these measured dependencies to the region near superconducting transition allows to make a calibration of asymmetric superconducting loops as quantum detector of noise. The calibration restores an amplitude profile of the noise pulses from a measured temperature dependence of an amplitude of the quantum oscillations V(Φ/Φ0) induced by this noise. It is found that rectification efficiency, determined as relation of the maximum amplitude of the quantum oscillations V(Φ/Φ0) to the ac current amplitude inducing it, decreases near superconducting transition Tc. High efficiency of rectification observed below Tc is consequence of irreversibility of the current-voltage curves. Increase of the rectification efficiency is achieved in multiple series connected loop structures.
The quantum rectification effect observed on asymmetric superconducting loops is proposed to use as a basic of a noise detector with maximum sensitivity. The measurements show that a critical amplitude of noise or ac current decreases down to zero near superconducting transition, Tc, just as superconducting critical current. Therefore any how weak noise, right down to the equilibrium one, can induce the quantum oscillations of the dc voltage near Tc. The transformation of the power of random noise into the dc power observed on asymmetric superconducting loops gives very important advantage: even very weak noise can give enough high output power in a system with large number of loops.
Magnetic quantum periodicity in the dc voltage is observed when asymmetric rings are switched between superconducting and normal state by a noise or ac current. This quantum effect is used for the detection of a non-equilibrium noise using a system of 667 asymmetric aluminum rings of 1 μm diameter connected in series. Any noise down to the equilibrium one can be detected with large number of asymmetric rings. The equilibrium noise can induce the dc voltage close to the superconducting transition. In our sample we observe the dc voltage oscillation only below the superconducting transition.
We have measured periodic oscillations of rectified dc voltage versus magnetic field Vdc(B){V}_{dc}(B)Vdc​(B) in a superconducting aluminum thin-film circular-asymmetric figure-of-eight microstructure threaded by a magnetic flux and biased with a sinusoidal alternating current (without a dc component) near the critical temperature. The Fourier spectra of these Vdc(B){V}_{dc}(B)Vdc​(B) functions contain fundamental frequencies representing periodic responses of the larger and smaller asymmetric circular loops, composing the microstructure, to the magnetic field. The higher harmonics of the obtained fundamental frequencies result from the nonsinusoidal character of loop circulating currents. The presence of the difference and summation frequencies in these spectra points to the interaction between the quantum states of both loops. Magnitudes of the loop responses to the bias ac and magnetic field vary with temperature and the bias current amplitude, both in absolute values and with respect to each other. The strongest loop response appears when the average resistive state of the loop corresponds to the midpoint of the superconducting-normal phase transition.
The interaction between the quantum states of two circularly asymmetric superconducting aluminum rings forming figure eight, threaded by a magnetic flux and biased by an external sinusoidal ac current with zero dc component, has been investigated. Quantum oscillations in the dependence V dc(B) of the rectified dc voltage on magnetic field for these structures have been measured at different external currents and temperatures close to critical. Fourier and wavelet analyses of the function V dc(B) have revealed, along with the two fundamental ring frequencies, various combination frequencies; this fact is indicative of interaction in the structure. Deviation of the function V dc(B) from oddness with respect to the magnetic field direction has been found for the first time.
We investigate theoretically the V-I characteristics and voltage noise of superconducting tunnel junctions with small critical current via the matrix-continued-fraction method. Special attention is paid to the large hysteresis in the V-I characteristics and to the voltage-noise anomaly observed in preliminary experiments. The current dependence of the voltage noise shows a strong asymmetry between the forward and backward current ramping and a discontinuous change of the noise close to its measured maximum occurring at the switching current. We show that both the large hysteresis and the voltage noise anomaly in this current-biased setup are a consequence of the influence of junction's electromagnetic environment. Typically, the voltage-noise dependence on the junction current parametrized by the external drive contains a loop which is, however, not observed experimentally because of the implementation of the junction-current ramp. Skipping a part of the loop is responsible for the observed hysteresis as well as the noise anomaly.
We consider a superconducting loop with two weak links that encloses a magnetic flux. The weak links are unequal and are treated as Josephson junctions with non-sinusoidal phase dependence. We devise a model that takes into account the fluctuation of the critical currents, due to the fluctuations of the order parameter in the weak links. These fluctuations are important near the onset of superconductivity; in this regime they may significantly weaken and eventually disconnect the superconducting loop. As a consequence of these fluctuations and of the resistive noise in the junctions, the average dc voltage does not vanish. Our model can be easily extended to provide a qualitative description of a recent experiment.