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:1805.05198 · Physical Review Applied

Escape of a Driven Quantum Josephson Circuit into Unconfined States

Raphaël Lescanne, Lucas Verney, Quentin Ficheux, Michel Devoret, Benjamin Huard, Mazyar Mirrahimi, Zaki Leghtas

Published Jan 16, 2019• 89 citations
arXivHTMLPDF

Abstract

Strongly driven superconducting Josephson circuits are instrumental in emulating a variety of Hamiltonians that are useful for quantum information processing. However, such a time-dependent, nonlinear, open quantum system can display complex dynamics that lead to degradation of coherence times, instabilities, and chaotic behavior. Here the authors observe an instability that results in the escape of a circuit's mode into states that are not confined by the Josephson cosine potential. This work guides us toward circuit designs that prevent instabilities, and thus are suitable for parametric pumping and quantum information processing.

DOI
10.1103/physrevapplied.11.014030

Related papers

Structural Instability of Driven Josephson Circuits Prevented by an Inductive Shunt

Lucas Verney, Raphaël Lescanne, Michel Devoret +2 more

Strongly driven superconducting circuits are a versatile platform to implement a multitude of Hamiltonians for quantum computation, simulation, and sensing. Unfortunately, they can display complex dynamics with instabilities, so predicting and preventing these instabilities is crucial for applications. This paper proposes an inductively shunted transmon qubit as the elementary circuit optimized for strong parametric drives. Developing a numerical approach that avoids the limitations of perturbative analysis, the authors demonstrate that adding the inductive shunt significantly extends the range of pump powers in which the circuit is stable.

arXiv:1805.07542•Physical Review Applied•Feb 1, 2019•50 citations

Structurally Stable Subharmonic Regime of a Driven Quantum Josephson Circuit

Michiel Burgelman, Pierre Rouchon, Alain Sarlette +1 more

Driven quantum nonlinear oscillators, while essential for quantum technologies, are generally prone to complex chaotic dynamics that fall beyond the reach of perturbative analysis. By focusing on subharmonic bifurcations of a harmonically driven oscillator, we provide a recipe for the choice of the oscillator's parameters that ensures a regular dynamical behavior independently of the driving strength. We show that this suppression of chaotic phenomena is compatible with a strong quantum nonlinear effect reflected by the confinement rate in the degenerate manifold spanned by stable subharmonic orbits.

arXiv:2206.14631•Physical Review Applied•Dec 15, 2022•11 citations

Collapse and Inversion of the Josephson Potential in a Strongly Driven Superconducting Circuit

Sercan Deve, Marius Villiers, Marijn A. Morssink +2 more

Superconducting circuits embedding Josephson junctions leverage microwave drives for control and measurement of quantum states. Although increasing the drive power is desirable for improving the efficiency of these operations, it eventually triggers unwanted transitions to uncontrolled states. While careful choice of circuit symmetries and parameters can mitigate these effects, the presence of spurious circuit modes spoils the resilience to high power. In this work, we engineer a transmon-resonator system free of any detrimental unwanted transitions. This resilience enables us to access drive powers at which we uncover a remarkable physical phenomenon: the collapse and inversion of the Josephson potential. Through spectroscopy and readout experiments, we confirm that the driven potential goes to zero and inverts as the power increases. The inversion corresponds to the dynamical stabilization of the transmon at its unstable equilibrium point, directly analogous to an inverted pendulum. This result reveals a new limitation of strongly driven superconducting circuits beyond drive-induced transitions. In addition, the dynamical renormalization of the Josephson potential opens up novel avenues for the control of superconducting circuits, and the autonomous stabilization of noise-resilient quantum states.

quant-pharXiv:2607.14344•Jul 17, 2026•0 citations

Nonlinear Optics Quantum Computation and Quantum Simulation with Circuit-QED

Prabin Adhikari

Superconducting quantum circuits are a promising approach for realizations of large scale quantum information processing and quantum simulations. The Josephson junction, which forms the basis of superconducting circuits, is the only known nonlinear non-dissipative circuit element, and its inherent nonlinearities have found many different applications. In this thesis I discuss specific implementations of these circuits. I show that strong two-photon nonlinearities can be induced by coupling photons in the microwave domain to Josephson nonlinearities. I then propose a method to simulate a parent Hamiltonian that can potentially be used to observe fractional quantum Hall states of light. I will also explore how superconducting circuits can be used to modify system-bath couplings to emulate a chemical potential for photons. Finally, I consider the limitations of devising a scheme to couple superconducting circuits to trapped ions, and consider the challenges for such hybrid approaches.

Bulletin of the American Physical Society•Jan 1, 2014•0 citations

Atomic Josephson parametric amplifier

Vijay Pal Singh, Luigi Amico A, Ludwig Mathey

We study the dynamics of a driven atomic Josephson junction that we propose as a parametric amplifier. By periodically modulating the position of the barrier, we induce a small current across the junction, serving as our input signal. The pump field is implemented by modulating the barrier height at twice the Josephson plasma frequency. The resulting dynamics exhibit parametric amplification of the signal through nonlinear mixing between the signal and pump fields, which is encoded in a specific microscopic pattern of density waves and phase excitations that can be addressed within the experimental cold-atom capabilities. This work paves the way for tunable amplifiers in atomtronic circuits, with potential applications in several fields including precision measurements and quantum information processing. At the same time, our analysis provides the microscopic explanation of the general notion of parametric amplification occurring in nonlinear coherent devices.

arXiv:2503.20890•Physical Review Research•Feb 11, 2026•1 citation

Dynamics of an ion coupled to a parametric superconducting circuit

Dvir Kafri, Prabin Adhikari, Jacob M. Taylor

Superconducting circuits and trapped ions are promising architectures for quantum information processing. However, the natural frequencies for controlling these systems---radio-frequency ion control and microwave domain superconducting qubit control---make direct Hamiltonian interactions between them weak. In this paper we describe a technique for coupling a trapped ion's motion to the fundamental mode of a superconducting circuit, by applying to the circuit a carefully modulated external magnetic flux. In conjunction with a nonlinear element (Josephson junction), this gives the circuit an effective time-dependent inductance. We then show how to tune the external flux to generate a resonant coupling between the circuit and ion's motional mode and discuss the limitations of this approach compared to using a time-dependent capacitance.

arXiv:1504.03993•Physical Review A•Jan 14, 2016•4 citations
Strongly driven superconducting Josephson circuits are instrumental in emulating a variety of Hamiltonians that are useful for quantum information processing. However, such a time-dependent, nonlinear, open quantum system can display complex dynamics that lead to degradation of coherence times, instabilities, and chaotic behavior. Here the authors observe an instability that results in the escape of a circuit's mode into states that are not confined by the Josephson cosine potential. This work guides us toward circuit designs that prevent instabilities, and thus are suitable for parametric pumping and quantum information processing.
Strongly driven superconducting circuits are a versatile platform to implement a multitude of Hamiltonians for quantum computation, simulation, and sensing. Unfortunately, they can display complex dynamics with instabilities, so predicting and preventing these instabilities is crucial for applications. This paper proposes an inductively shunted transmon qubit as the elementary circuit optimized for strong parametric drives. Developing a numerical approach that avoids the limitations of perturbative analysis, the authors demonstrate that adding the inductive shunt significantly extends the range of pump powers in which the circuit is stable.
Driven quantum nonlinear oscillators, while essential for quantum technologies, are generally prone to complex chaotic dynamics that fall beyond the reach of perturbative analysis. By focusing on subharmonic bifurcations of a harmonically driven oscillator, we provide a recipe for the choice of the oscillator's parameters that ensures a regular dynamical behavior independently of the driving strength. We show that this suppression of chaotic phenomena is compatible with a strong quantum nonlinear effect reflected by the confinement rate in the degenerate manifold spanned by stable subharmonic orbits.
Superconducting circuits embedding Josephson junctions leverage microwave drives for control and measurement of quantum states. Although increasing the drive power is desirable for improving the efficiency of these operations, it eventually triggers unwanted transitions to uncontrolled states. While careful choice of circuit symmetries and parameters can mitigate these effects, the presence of spurious circuit modes spoils the resilience to high power. In this work, we engineer a transmon-resonator system free of any detrimental unwanted transitions. This resilience enables us to access drive powers at which we uncover a remarkable physical phenomenon: the collapse and inversion of the Josephson potential. Through spectroscopy and readout experiments, we confirm that the driven potential goes to zero and inverts as the power increases. The inversion corresponds to the dynamical stabilization of the transmon at its unstable equilibrium point, directly analogous to an inverted pendulum. This result reveals a new limitation of strongly driven superconducting circuits beyond drive-induced transitions. In addition, the dynamical renormalization of the Josephson potential opens up novel avenues for the control of superconducting circuits, and the autonomous stabilization of noise-resilient quantum states.
Superconducting quantum circuits are a promising approach for realizations of large scale quantum information processing and quantum simulations. The Josephson junction, which forms the basis of superconducting circuits, is the only known nonlinear non-dissipative circuit element, and its inherent nonlinearities have found many different applications. In this thesis I discuss specific implementations of these circuits. I show that strong two-photon nonlinearities can be induced by coupling photons in the microwave domain to Josephson nonlinearities. I then propose a method to simulate a parent Hamiltonian that can potentially be used to observe fractional quantum Hall states of light. I will also explore how superconducting circuits can be used to modify system-bath couplings to emulate a chemical potential for photons. Finally, I consider the limitations of devising a scheme to couple superconducting circuits to trapped ions, and consider the challenges for such hybrid approaches.
We study the dynamics of a driven atomic Josephson junction that we propose as a parametric amplifier. By periodically modulating the position of the barrier, we induce a small current across the junction, serving as our input signal. The pump field is implemented by modulating the barrier height at twice the Josephson plasma frequency. The resulting dynamics exhibit parametric amplification of the signal through nonlinear mixing between the signal and pump fields, which is encoded in a specific microscopic pattern of density waves and phase excitations that can be addressed within the experimental cold-atom capabilities. This work paves the way for tunable amplifiers in atomtronic circuits, with potential applications in several fields including precision measurements and quantum information processing. At the same time, our analysis provides the microscopic explanation of the general notion of parametric amplification occurring in nonlinear coherent devices.
Superconducting circuits and trapped ions are promising architectures for quantum information processing. However, the natural frequencies for controlling these systems---radio-frequency ion control and microwave domain superconducting qubit control---make direct Hamiltonian interactions between them weak. In this paper we describe a technique for coupling a trapped ion's motion to the fundamental mode of a superconducting circuit, by applying to the circuit a carefully modulated external magnetic flux. In conjunction with a nonlinear element (Josephson junction), this gives the circuit an effective time-dependent inductance. We then show how to tune the external flux to generate a resonant coupling between the circuit and ion's motional mode and discuss the limitations of this approach compared to using a time-dependent capacitance.