Coexistence of single- and multi-photon processes due to longitudinal couplings between superconducting flux qubits and external fields

Liu, Yu-xi; Yang, Chengxi; Sun, Hui-Chen; Wang, Xiang-Bin

doi:10.1088/1367-2630/16/1/015031

Cited by 46 publications

(34 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As discussed in Refs. [49][50][51][52], coupling a resonator with a superconducting qubit of longitudinal form will induce multiphonon (multiphoton) processes.…”

Section: B Summary Of Our Proposalmentioning

confidence: 99%

Method for observing robust and tunable phonon blockade in a nanomechanical resonator coupled to a charge qubit

Wang

Miranowicz

et al. 2016

Phys. Rev. A

View full text Add to dashboard Cite

Phonon blockade is a purely quantum phenomenon, analogous to Coulomb and photon blockades, in which a single phonon in an anharmonic mechanical resonator can impede the excitation of a second phonon. We propose an experimental method to realize phonon blockade in a driven harmonic nanomechanical resonator coupled to a qubit, where the coupling is proportional to the second-order nonlinear susceptibility χ (2) . This is in contrast to the standard realizations of phonon and photon blockade effects in Kerr-type χ (3) nonlinear systems. The nonlinear coupling strength can be adjusted conveniently by changing the coherent drive field. As an example, we apply this model to predict and describe phonon blockade in a nanomechanical resonator coupled to a Cooperpair box (i.e., a charge qubit) with a linear longitudinal coupling. By obtaining the solutions of the steady state for this composite system, we give the conditions for observing strong antibunching and sub-Poissonian phonon-number statistics in this induced second-order nonlinear system. Besides using the qubit to produce phonon blockade states, the qubit itself can also be employed to detect blockade effects by measuring its states. Numerical simulations indicate that the robustness of the phonon blockade, and the sensitivity of detecting it, will benefit from this strong induced nonlinear coupling.

show abstract

“…As discussed in Refs. [49][50][51][52], coupling a resonator with a superconducting qubit of longitudinal form will induce multiphonon (multiphoton) processes.…”

Section: B Summary Of Our Proposalmentioning

confidence: 99%

Method for observing robust and tunable phonon blockade in a nanomechanical resonator coupled to a charge qubit

Wang

Miranowicz

et al. 2016

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…and(29) for the frequencies ω k of electric modes in the loop and the coupling constants α k , respectively, complete the mapping of the Josephson junction ring with a weak element to a generic spin-boson model of section 3.…”

mentioning

confidence: 99%

Coherent dynamics in long fluxonium qubits

2015

View full text Add to dashboard Cite

We analyze the coherent dynamics of a fluxonium device (Manucharyan et al 2009 Science 326 113) formed by a superconducting ring of Josephson junctions in which strong quantum phase fluctuations are localized exclusively on a single weak element. In such a system, quantum phase tunnelling by π 2 occurring at the weak element couples the states of the ring with supercurrents circulating in opposite directions, while the rest of the ring provides an intrinsic electromagnetic environment of the qubit. Taking into account the capacitive coupling between nearest neighbors and the capacitance to the ground, we show that the homogeneous part of the ring can sustain electrodynamic modes which couple to the two levels of the flux qubit. In particular, when the number of Josephson junctions is increased, several low-energy modes can have frequencies lower than the qubit frequency. This gives rise to a quasiperiodic dynamics, which manifests itself as a decay of oscillations between the two counterpropagating current states at short times, followed by oscillation-like revivals at later times. We analyze how the system approaches such a dynamics as the ring's length is increased and discuss possible experimental implications of this nonadiabatic regime. 2 occur due to quantum tunnelling with an amplitude  , which in the limit ≫ E E J C reads [6,21,25,41]

show abstract

“…The existence of the longitudinal coupling between superconducting qubits and applied magnetic fields were shown35, when the inversion symmetry of the potential energy of the superconducting qubit is broken. When a superconducting flux qubit is driven by a strong ac field, the time dependent Hamiltonian, which describes the longitudinal coupling is given by…”

Section: Resultsmentioning

confidence: 99%

A graph-theoretical representation of multiphoton resonance processes in superconducting quantum circuits

Jooya

Reihani

Chu

2016

Sci Rep

View full text Add to dashboard Cite

We propose a graph-theoretical formalism to study generic circuit quantum electrodynamics systems consisting of a two level qubit coupled with a single-mode resonator in arbitrary coupling strength regimes beyond rotating-wave approximation. We define colored-weighted graphs, and introduce different products between them to investigate the dynamics of superconducting qubits in transverse, longitudinal, and bidirectional coupling schemes. The intuitive and predictive picture provided by this method, and the simplicity of the mathematical construction, are demonstrated with some numerical studies of the multiphoton resonance processes and quantum interference phenomena for the superconducting qubit systems driven by intense ac fields.

show abstract

Coexistence of single- and multi-photon processes due to longitudinal couplings between superconducting flux qubits and external fields

Cited by 46 publications

References 70 publications

Method for observing robust and tunable phonon blockade in a nanomechanical resonator coupled to a charge qubit

Method for observing robust and tunable phonon blockade in a nanomechanical resonator coupled to a charge qubit

Coherent dynamics in long fluxonium qubits

A graph-theoretical representation of multiphoton resonance processes in superconducting quantum circuits

Contact Info

Product

Resources

About