Crossover from weak to strong coupling regime in dispersive circuit QED

Abstract

We study the decoherence of a superconducting qubit due to the dispersive coupling to a damped harmonic oscillator. We go beyond the weak qubit-oscillator coupling, which we associate with a phase Purcell effect, and enter into a strong coupling regime, with qualitatively different behavior of the dephasing rate. We identify and give a physicaly intuitive discussion of both decoherence mechanisms. Our results can be applied, with small adaptations, to a large variety of other physical systems, e. g. trapped ions and cavity QED, boosting theoretical and experimental decoherence studies.

Published version

References in corpus (20)

• Circuit Quantum Electrodynamics: Coherent Coupling of a Single Photon to a Cooper Pair Box
• Cavity quantum electrodynamics for superconducting electrical circuits: an architecture for quantum computation
• Quantum state engineering with Josephson-junction devices
• Manipulating the Quantum State of an Electrical Circuit
• Resolving photon number states in a superconducting circuit
• Quantum oscillations in two coupled charge qubits
• Mach-Zehnder Interferometry in a Strongly Driven Superconducting Qubit
• Qubit-photon interactions in a cavity: Measurement induced dephasing and number splitting
• Quantum information processing with superconducting qubits in a microwave field
• Dephasing of a superconducting qubit induced by photon noise
• Coherent dynamics of a Josephson charge qubit
• Internal Consistency of Fault-Tolerant Quantum Error Correction in Light of Rigorous Derivations of the Quantum Markovian Limit
• Nondestructive readout for a superconducting flux qubit
• Flux Qubits and Readout Device with Two Independent Flux Lines
• High fidelity measurement and quantum feedback control in circuit QED
• Entanglement spectroscopy of a driven solid-state qubit and its detector
• Exploiting environmental resonances to enhance qubit quality factors
• An asymptotical von-Neumann measurement strategy for solid-state qubits
• Dissipation and decoherence in a quantum oscillator
• Phase-space theory for dispersive detectors of superconducting qubits

Cited by in corpus (8)

• Photon Shot Noise Dephasing in the Strong-Dispersive Limit of Circuit QED
• Circuit QED with fluxonium qubits: theory of the dispersive regime
• Probing the quantum coherence of a nanomechanical resonator using a superconducting qubit: I. Echo scheme
• Theory of Josephson Photomultipliers: Optimal Working Conditions and Back Action
• Stochastic Wave-Function Unravelling of the Generalized Lindblad Master Equation
• Photon-noise-tolerant dispersive readout of a superconducting qubit using a nonlinear Purcell filter
• Relaxation of a qubit measured by a driven Duffing oscillator
• Vacuum-fluctuation-induced Dephasing of a Qubit in Circuit Quantum Electrodynamics