Kinetics of the superconducting charge qubit in the presence of a quasiparticle

Abstract

We investigate the energy and phase relaxation of a superconducting qubit caused by a single quasiparticle. In our model, the qubit is an isolated system consisting of a small island (Cooper-pair box) and a larger superconductor (reservoir) connected with each other by a tunable Josephson junction. If such system contains an odd number of electrons, then even at lowest temperatures a single quasiparticle is present in the qubit. Tunneling of a quasiparticle between the reservoir and the Cooper-pair box results in the relaxation of the qubit. We derive master equations governing the evolution of the qubit coherences and populations. We find that the kinetics of the qubit can be characterized by two time scales - quasiparticle escape time from reservoir to the box, ${\Gamma }_{in}^{-1}$, and quasiparticle relaxation time $\tau$. The former is determined by the dimensionless normal-state conductance $g_T$ of the Josephson junction and one-electron level spacing ${\delta }_r$ in the reservoir (${\Gamma }_{in}\sim g_T{\delta }_r$), and the latter is due to electron-phonon interaction. We find that phase coherence is damped on the time scale of ${\Gamma }_{in}^{-1}$. The qubit energy relaxation depends on the ratio of the two characteristic times, $\tau$ and ${\Gamma }_{in}^{-1}$, and also on the ratio of temperature $T$ to the Josephson energy $E_J$.

arXiv comment12 pages, 4 figures, final version as published in PRB, some changes, reference added

References in corpus (14)

• 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
• Coherent control of macroscopic quantum states in a single-Cooper-pair box
• The Physical Implementation of Quantum Computation
• Manipulating the Quantum State of an Electrical Circuit
• Quantum noise in the Josephson charge qubit
• Nonequilibrium quasiparticles and $2e$ periodicity in single-Cooper-pair transistors
• Quantum master equation for a system influencing its environment
• Quasiparticle decay rate of Josephson charge qubit oscillations
• Time-domain measurements of quasiparticle tunneling rates in a single-Cooper-pair transistor
• Quasiparticle number fluctuations in superconductors
• Free Evolution of Superposition States in a Single Cooper Pair Box
• Weak Localization in Metallic Granular Media

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