Purification in Rapid Repeated Interaction Systems

Abstract

We investigate the open dynamics of a quantum system when it is rapidly repeatedly updated by a quantum channel. Specifically, we analyze when this dynamics can purify the system. We develop a necessary and sufficient condition for such purification effects to occur and characterize their strength. We thoroughly analyze the specific scenario of a quantum system undergoing rapid unitary interactions with a sequence of ancillary quantum systems. We find that while the purification effects are generally present, in order for these effects to be strong compared to the decoherence effects the interaction Hamiltonian must have a minimum degree of complexity. Specifically, a tensor product interaction ${\hat{Q}}_{\text{S}}\otimes {\hat{R}}_{\text{A}}$, as well as many common light-matter interactions cannot purify efficiently.

14 Pages. RevTeX 4.1

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Cited by in corpus (8)

• Nonequilibrium Dynamics with Finite-Time Repeated Interactions
• Quantum master equations for entangled qubit environments
• The Unruh effect in slow motion
• Gaussian ancillary bombardment
• A classification of open Gaussian dynamics
• Interpolated Collision Model Formalism
• Thermal Contact: Mischief and Time Scales
• Sensitivity of Measurement-Based Purification Processes to Inner Interactions