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:1709.06595 · IEEE Transactions on Applied Superconductivity

Dynamic Microwave Impedance of Dc-Biased Josephson Fluxonic Diode in the Presence of Magnetic Field and RF Drive

Hamed Mehrara, Farshid Raissi, Alireza Erfanian, S. Hossein Mohseni Armaki, Soheil Abdollahi

Published Feb 22, 2018• 3 citations
arXivHTMLPDF

Abstract

Josephson Fluxonic Diode (JFD) provides a very nonlinear characteristic in comparison with a long Josephson junction at microwave frequencies. This nonlinearity is highly accentuated by creation and dynamics of vortex-antivortex pairs in two disparate modes of operation; forward and reverse-bias. Experimental detection of microwave frequencies through this device is not solely dependent on the geometry and seems to change drastically with the different operating condition. This paper attempts to understand the microwave characteristic of this device with respect to its bias and control current and rf-exposed boundary conditions defined in RCSJ model of JFD. Based on the simulation results, for a finite length of a JFD excited by a low-amplitude microwave signal below its plasma frequency, control current increases the rate of vortex-antivortex pair generation and fine-tunes the microwave resistance (Rω) up to an order of magnitude more than its zero magnetic field resistance (R0). Under this circumstance, adding the bias current which can move generated vortex-antivortex pairs causes a substantial increase up to three orders of magnitude compared to R0either in forward or reverse-bias, while damping coefficient 1/√βc(βcis Stewart-McCumber parameter of Josephson junction) can limit this increase. It has also been shown that the variation of polarity, frequency, or amplitude of incoming microwave signal can impact on the impedance due to its relation with pair generation rate and so causes variations in observed impedance both in linear and nonlinear form. According to the results, low-microwave impedance of a JFD can be multiplied externally using biasing sets to match with high-impedance sources, which justifies its detection mechanism at microwave frequency.

DOI
10.1109/tasc.2018.2807759

Related papers

Long Josephson junction embedded into a planar resonator at microwave frequencies: Numerical simulation of fluxon dynamics

E. Goldobin, Alexander M. Klushin, M. Siegel +1 more

We have investigated numerically a system consisting of a long Josephson junction embedded into a microstrip resonator. For such a configuration the Josephson vortex dynamics in the junction is driven by the oscillating currents in the resonator. We have calculated the complex impedance of the junction at the resonant frequency. The Q factor of the resonator and the change of the resonant frequency of the whole system can then be easily calculated knowing the parameters of the resonator without Josephson junction. The fluxon dynamics and the complex impedance of the junction are simulated for different values of the junction length, damping, dc bias current, and dc magnetic field. This allows us to explain the behavior of the impedance of the junction and different loss mechanisms. In particular, we predict a nonmonotonic dependence of the both real and imaginary parts of the impedance on the amplitude of the oscillating current in the resonator for some range of parameters. Our results show that such a combination of active and passive superconducting elements forms a rather interesting nonlinear physical system which might be useful for development of tunable/switchable superconducting resonators and suggests an experimental technique for detecting trapped vortices in long junctions.

Journal of Applied Physics•Aug 30, 2002•7 citations

Simulation Results on Submillimeter Wave Detection by Josephson Fluxonic Diode and a Method to Address Its Focal Plane Array

Farshid Raissi

Application of radiation to a reverse-biased Josephson fluxonic diode (JFD) creates vortex-antivortex pairs. Pairs are created at each peak of sinusoidal radiation and move under the application of the bias current, exhibiting a voltage which depends on the frequency of incoming radiation. Simulation results for frequencies ranging from 50 to 700 GHz have been obtained. A simple and practical addressing scheme is proposed for a matrix of JFD pixels. Ease of fabrication, inherent gain, simultaneous determination of amplitude and frequency of radiation, large output current, and simple addressability in focal plane arrays are among the advantages of JFD as a direct submillimeter wave detector

IEEE Transactions on Applied Superconductivity•Mar 1, 2006•4 citations

Modeling of the josephson fluxonic diode

Farshid Raissi

A forward bias Josephson fluxonic diode exhibits a linear I-V curve whose slope is a function of the Stewart-McCumber loss parameter /spl beta/, the length of the junction, critical current density and the magnitude of the applied control current. This linear I-V curve lacks resonance structure and does not exhibit a flux flow step. A modeling which matches experimental results is presented.

IEEE Transactions on Applied Superconductivity•Sep 1, 2003•9 citations

Negative resistance effects with Josephson junctions

Helmut Kanter

Conventional negative resistance effects can be generated with a Josephson junction quite similar to that obtained with Varactor diodes, with the additional advantage that the internal, self-generated oscillations serve as a pump, i. e., only a dc source is needed instead of a high frequency pump source. However, another negative resistance effect typical for a Josephson junction is possible as has been predicted recently for the current controlled, highly damped junction model. The effect has recently been demonstrated experimentally at 9 GHz. Characteristically, the pump (Josephson) frequency is smaller than the frequency of the amplified signal and the pump mechanism is effective over a broad range of frequencies in contrast to the conventional parametric negative resistance effect where the pump frequency exceeds that of the signal and idler and where the frequency of operation is limited to a narrow range. The broad-band feature renders the amplifier operation uncritical to tuning and bias voltage fluctuations. The fact that the junction is the element of lowest impedance in the circuit alleviates to a degree the matching problem generally encountered with Josephson contacts. An assessment of the competitiveness of this effect in microwave technology is given.

Revue de Physique Appliquée•Jan 1, 1974•0 citations

Comparison of simulation and experiment for a Josephson fluxonic diode

Farshid Raissi, J.E. Nordman

With a slight modification to the control line and its bias configuration, a long Josephson junction vortex flow transistor structure can become a so-called fluxonic diode containing fluxon and antifluxon "doped" regions in analogy to a pn junction. Such structures have been made with Nb-Pb tunnel junctions allowing testing of the same device with a number of different doping configurations. This paper compares experimental results with a one dimensional numerical simulation. Different configurations for the diode have been modeled with Stewart-McCumber loss parameters ranging between 50 and 1400. The simulation clarifies the origin of a number of experimental observations, including a peculiar dependence of resonance induced step behavior on loss parameter, and a limit to the value of the gradient of doping in the transition region below which an asymmetric I-V curve representing forward and reverse biases is obtained. In forward bias, the I-V curve above a threshold current is roughly linear and devoid of resonance structure, provided injection of carriers occurs from one region to the other. Injection is a function of loss and the asymmetry of doping.>

IEEE Transactions on Applied Superconductivity•Jun 1, 1995•12 citations

Review of microwave distributed superconducting vortex-flow transistor amplifiers

R.C. Yalamanchili, ZHENG AN QIU, Yen-Chu Wang

The dynamics of fluxons in the vortex flow transistor (VFT) has been much studied. The fluxon transit time determines the fundamental speed limit of operation. Since fluxons can travel at the velocity of electromagnetic waves in the junction, the VFT has the potential for operating in high frequency systems ( ≈ 100 GHz). However, owing to the low input and output impedance of the VFT, use of the device in a conventional circuit would be quite limited. A distributed amplifier configuration consisting of many VFTs has been proposed to remedy the problems of low impedance levels. However, the realization of such an amplifier circuit at microwave or millimetre wave frequencies depends on obtaining a circuit model. In this paper, microwave superconducting VFT distributed amplifiers using the balanced control technique is reviewed. This kind of amplifier has the advantage that the capacitive feedthrough effect is decreased to a negligible extent. This is the major limiting factor for high frequency applications. The self-field effect which makes the current step inclined is reduced by injecting bias current only around the region of one end of the junction thus obtaining steeper I- V characteristics. With the asymmetric geometry, the slope of the current step is about one hundred times steeper than those obtained with the conventional overlap geometry. Owing to the diamagnetic behaviour of the Josephson junction, a little of the magnetic field induced by the current in the control line is allowed to penetrate the junction. Thus, the transresistance rm of a VFT is very small. Some methods for maximizing rm and minimizing the output impedance r0 also appear in this review. The feasibility of fabricating VFT distributed amplifiers using low-Tc superconducting material has been demonstrated. The power gain of the amplifier can be as high as 15 dB with a flat frequency response.

International Journal of Electronics•Sep 1, 1992•3 citations
Josephson Fluxonic Diode (JFD) provides a very nonlinear characteristic in comparison with a long Josephson junction at microwave frequencies. This nonlinearity is highly accentuated by creation and dynamics of vortex-antivortex pairs in two disparate modes of operation; forward and reverse-bias. Experimental detection of microwave frequencies through this device is not solely dependent on the geometry and seems to change drastically with the different operating condition. This paper attempts to understand the microwave characteristic of this device with respect to its bias and control current and rf-exposed boundary conditions defined in RCSJ model of JFD. Based on the simulation results, for a finite length of a JFD excited by a low-amplitude microwave signal below its plasma frequency, control current increases the rate of vortex-antivortex pair generation and fine-tunes the microwave resistance (Rω) up to an order of magnitude more than its zero magnetic field resistance (R0). Under this circumstance, adding the bias current which can move generated vortex-antivortex pairs causes a substantial increase up to three orders of magnitude compared to R0either in forward or reverse-bias, while damping coefficient 1/√βc(βcis Stewart-McCumber parameter of Josephson junction) can limit this increase. It has also been shown that the variation of polarity, frequency, or amplitude of incoming microwave signal can impact on the impedance due to its relation with pair generation rate and so causes variations in observed impedance both in linear and nonlinear form. According to the results, low-microwave impedance of a JFD can be multiplied externally using biasing sets to match with high-impedance sources, which justifies its detection mechanism at microwave frequency.
We have investigated numerically a system consisting of a long Josephson junction embedded into a microstrip resonator. For such a configuration the Josephson vortex dynamics in the junction is driven by the oscillating currents in the resonator. We have calculated the complex impedance of the junction at the resonant frequency. The Q factor of the resonator and the change of the resonant frequency of the whole system can then be easily calculated knowing the parameters of the resonator without Josephson junction. The fluxon dynamics and the complex impedance of the junction are simulated for different values of the junction length, damping, dc bias current, and dc magnetic field. This allows us to explain the behavior of the impedance of the junction and different loss mechanisms. In particular, we predict a nonmonotonic dependence of the both real and imaginary parts of the impedance on the amplitude of the oscillating current in the resonator for some range of parameters. Our results show that such a combination of active and passive superconducting elements forms a rather interesting nonlinear physical system which might be useful for development of tunable/switchable superconducting resonators and suggests an experimental technique for detecting trapped vortices in long junctions.
Application of radiation to a reverse-biased Josephson fluxonic diode (JFD) creates vortex-antivortex pairs. Pairs are created at each peak of sinusoidal radiation and move under the application of the bias current, exhibiting a voltage which depends on the frequency of incoming radiation. Simulation results for frequencies ranging from 50 to 700 GHz have been obtained. A simple and practical addressing scheme is proposed for a matrix of JFD pixels. Ease of fabrication, inherent gain, simultaneous determination of amplitude and frequency of radiation, large output current, and simple addressability in focal plane arrays are among the advantages of JFD as a direct submillimeter wave detector
Conventional negative resistance effects can be generated with a Josephson junction quite similar to that obtained with Varactor diodes, with the additional advantage that the internal, self-generated oscillations serve as a pump, i. e., only a dc source is needed instead of a high frequency pump source. However, another negative resistance effect typical for a Josephson junction is possible as has been predicted recently for the current controlled, highly damped junction model. The effect has recently been demonstrated experimentally at 9 GHz. Characteristically, the pump (Josephson) frequency is smaller than the frequency of the amplified signal and the pump mechanism is effective over a broad range of frequencies in contrast to the conventional parametric negative resistance effect where the pump frequency exceeds that of the signal and idler and where the frequency of operation is limited to a narrow range. The broad-band feature renders the amplifier operation uncritical to tuning and bias voltage fluctuations. The fact that the junction is the element of lowest impedance in the circuit alleviates to a degree the matching problem generally encountered with Josephson contacts. An assessment of the competitiveness of this effect in microwave technology is given.
With a slight modification to the control line and its bias configuration, a long Josephson junction vortex flow transistor structure can become a so-called fluxonic diode containing fluxon and antifluxon "doped" regions in analogy to a pn junction. Such structures have been made with Nb-Pb tunnel junctions allowing testing of the same device with a number of different doping configurations. This paper compares experimental results with a one dimensional numerical simulation. Different configurations for the diode have been modeled with Stewart-McCumber loss parameters ranging between 50 and 1400. The simulation clarifies the origin of a number of experimental observations, including a peculiar dependence of resonance induced step behavior on loss parameter, and a limit to the value of the gradient of doping in the transition region below which an asymmetric I-V curve representing forward and reverse biases is obtained. In forward bias, the I-V curve above a threshold current is roughly linear and devoid of resonance structure, provided injection of carriers occurs from one region to the other. Injection is a function of loss and the asymmetry of doping.>
The dynamics of fluxons in the vortex flow transistor (VFT) has been much studied. The fluxon transit time determines the fundamental speed limit of operation. Since fluxons can travel at the velocity of electromagnetic waves in the junction, the VFT has the potential for operating in high frequency systems ( ≈ 100 GHz). However, owing to the low input and output impedance of the VFT, use of the device in a conventional circuit would be quite limited. A distributed amplifier configuration consisting of many VFTs has been proposed to remedy the problems of low impedance levels. However, the realization of such an amplifier circuit at microwave or millimetre wave frequencies depends on obtaining a circuit model. In this paper, microwave superconducting VFT distributed amplifiers using the balanced control technique is reviewed. This kind of amplifier has the advantage that the capacitive feedthrough effect is decreased to a negligible extent. This is the major limiting factor for high frequency applications. The self-field effect which makes the current step inclined is reduced by injecting bias current only around the region of one end of the junction thus obtaining steeper I- V characteristics. With the asymmetric geometry, the slope of the current step is about one hundred times steeper than those obtained with the conventional overlap geometry. Owing to the diamagnetic behaviour of the Josephson junction, a little of the magnetic field induced by the current in the control line is allowed to penetrate the junction. Thus, the transresistance rm of a VFT is very small. Some methods for maximizing rm and minimizing the output impedance r0 also appear in this review. The feasibility of fabricating VFT distributed amplifiers using low-Tc superconducting material has been demonstrated. The power gain of the amplifier can be as high as 15 dB with a flat frequency response.