Reduced visibility of quantum oscillations in the spin-boson model

Abstract

The loss of coherence of quantum oscillations is of fundamental interest as well as of practical importance in quantum computing. In solid-state experiments the oscillations show, next to the familiar exponential decay on time scales $T_{1/2}$, an overall loss of amplitude. We solve the spin-Boson for a large class of initial conditions without the Markov approximation at the pure dephasing point. It is shown that a loss of visibility occurs in the form of a fast initial drop for factorized initial conditions and an overall reduction for entangled initial conditions. This loss of amplitude is distict from $T_2$-decoherence with the difference being most drastic for environments with real or pseudo-gaps. This result is explained by bandwith effects in quantum noise as well as in terms of higher-order phase-breaking processes. For several experiments, such gapped environments are identified. We confirm that this physics is valid beyond the pure dephasing point.

13 pages, 2 figures; significant update

References in corpus (16)

• Superconducting Circuits and Quantum Information
• Decoherence in a superconducting quantum bit circuit
• Approaching Unit Visibility for Control of a Superconducting Qubit with Dispersive Readout
• Real-time dynamics in Quantum Impurity Systems: A Time-dependent Numerical Renormalization Group Approach
• Dephasing of a superconducting qubit induced by photon noise
• Scaling and Decoherence in the Out-of-Equilibrium Kondo Model
• Universal and measurable entanglement entropy in the spin-boson model
• Reducing decoherence of the confined exciton state in a quantum dot by pulse-sequence control
• On the conundrum of deriving exact solutions from approximate master equations
• LO Phonon-Induced Exciton Dephasing in Quantum Dots: An Exactly Solvable Model
• Asymmetry and decoherence in a double-layer persistent-current qubit
• Reduced Visibility of Rabi Oscillations in Superconducting Qubits
• Relaxation and Dephasing in a Flux-qubit
• Superconducting qubits
• Quantum Dissipative Dynamics of Entanglement in the Spin-Boson Model
• Single Qubit Rabi Oscillation Decohered by Many Two-Level Systems

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