Optimization of partially isolated quantum harmonic oscillator memory systems by mean square decoherence time criteria

• URL: http://arxiv.org/abs/2409.15720v1
• Date: Tue, 24 Sep 2024 04:10:27 GMT
• Title: Optimization of partially isolated quantum harmonic oscillator memory systems by mean square decoherence time criteria
• Authors: Igor G. Vladimirov, Ian R. Petersen,
• Abstract summary: Heisenberg picture quantum memories exploit their ability to retain initial conditions over a decoherence horizon. Using the quantum memoryherence time defined previously in terms of a fidelity threshold on a weighted mean-square deviation of the system variables, we apply this approach to a partially isolated subsystem.
• Score: 0.6138671548064356
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: This paper is concerned with open quantum harmonic oscillators with position-momentum system variables, whose internal dynamics and interaction with the environment are governed by linear quantum stochastic differential equations. A recently proposed approach to such systems as Heisenberg picture quantum memories exploits their ability to approximately retain initial conditions over a decoherence horizon. Using the quantum memory decoherence time defined previously in terms of a fidelity threshold on a weighted mean-square deviation of the system variables from their initial values, we apply this approach to a partially isolated subsystem of the oscillator, which is not directly affected by the external fields. The partial isolation leads to an appropriate system decomposition and a qualitatively different short-horizon asymptotic behaviour of the deviation, which yields a longer decoherence time in the high-fidelity limit. The resulting approximate decoherence time maximization over the energy parameters for improving the quantum memory performance is discussed for a coherent feedback interconnection of such systems.

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