Evaluation of Decoherence for Quantum Computing Architectures: Qubit System Subject to Time-Dependent Control

Abstract

We present an approach that allows quantifying decoherence processes in an open quantum system subject to external time-dependent control. Interactions with the environment are modeled by a standard bosonic heat bath. We develop two unitarity-preserving approximation schemes to calculate the reduced density matrix. One of the approximations relies on a short-time factorization of the evolution operator, while the other utilizes expansion in terms of the system-bath coupling strength. Applications are reported for two illustrative systems: an exactly solvable adiabatic model, and a model of a rotating-wave quantumcomputing gate function. The approximations are found to produce consistent results at short and intermediate times.

26 pages in PDF, 6 figures, 1 table; Typos corrected

References in corpus (9)

• Zeeman energy and spin relaxation in a one-electron quantum dot
• Decoherence Rate of Semiconductor Charge Qubit Coupled to Acoustic Phonon Reservoir
• Rigorous Born Approximation and beyond for the Spin-Boson Model
• Short-Time Decoherence for General System-Environment Interactions
• Charge Transport Through Open, Driven Two-Level Systems with Dissipation
• Additivity of decoherence measures for multiqubit quantum systems
• Evaluation of Decoherence for Quantum Control and Computing
• Short-time decoherence of Josephson charge qubit nonlinearly coupling with its environment
• Short-time decoherence of Josephson charge qubits

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• Quantitative Treatment of Decoherence
• Excitation spectrum as a resource for efficient two-qubit entangling gates