Decoherence dynamics of a qubit coupled to a quantum two-level system

Abstract

We study the decoherence dynamics of a qubit coupled to a quantum two-level system (TLS) in addition to its weak coupling to a background environment. We analyze the different regimes of behaviour that arise as the values of the different parameters are varied. We classify those regimes as two weak-coupling regimes, which differ by the relation between the qubit and TLS decoherence times, and a strong-coupling one. We also find analytic expressions describing the decoherence rates in the weak-coupling regimes, and we verify numerically that those expressions have a rather wide range of validity. Along with obtaining the above-mentioned results, we address the questions of qubit-TLS entanglement and the additivity of multiple TLS contributions. We also discuss the transition from weak to strong coupling as the parameters are varied, and we numerically determine the location of the boundary between the two regimes.

9 pages (two-column), 3 figures

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Cited by in corpus (12)

• Quantum algorithm for simulating the dynamics of an open quantum system
• Quantum mechanical approach to decoherence and relaxation generated by fluctuating environment
• Relaxation of Josephson qubits due to strong coupling to two-level systems
• Stabilizing and improving qubit coherence by engineering noise spectrum of two-level systems
• Nonclassicality of open circuit QED systems in the deep-strong coupling regime
• Probing internal bath dynamics by a Rabi oscillator-based detector
• Non-Markovian entanglement dynamics in coupled superconducting qubit systems
• Jaynes Cummings treatment of superconducting resonators with dielectric loss due to two-level systems
• Manifold algorithmic errors in quantum computers with static internal imperfections
• Implementing Genuine Multi-Qubit Entanglement of Two-Level-System Inside a Superconducting Phase Qubit
• Quantum deficits and correlations of two superconducting charge qubits
• Two coupled qubits under the influence of a minimal, phase-sensitive environment