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Measured Composite Collision Models: Quantum Trajectory Purities and Channel Divisibility
Konstantin Beyer1, Kimmo Luoma2, Tim Lenz1
1Institut für Theoretische Physik, Technische Universität Dresden, D-01062 Dresden, Germany.
Entropy (Basel, Switzerland)
|May 28, 2022
Summary
We explore quantum collision models using measurements to control system dynamics. Adjusting measurement strength on memory qubits tunes system evolution and affects average purity, showing measurement choice impacts quantum system behavior.
Area of Science:
- Quantum Information Science
- Quantum Dynamics
- Quantum Measurement Theory
Background:
- Composite quantum collision models offer a framework to study open quantum systems.
- Measurements on a system's memory can effectively probe and influence its dynamics.
Purpose of the Study:
- To investigate how measurements on the memory part of a composite quantum system influence its dynamics.
- To tune the dynamical map of a quantum system by adjusting measurement strength.
Main Methods:
- Utilizing a composite quantum collision model with adjustable measurement strength on the memory.
- Analyzing the divisibility of system dynamics for a two-qubit setup with symmetric and informationally complete measurements.
- Employing numerical simulations to demonstrate the generic nature of measurement performance.
Main Results:
- Measurement strength effectively tunes the dynamical map of the quantum system.
- Average asymptotic purity depends on the specific form of the measurement applied to the memory.
- The performance of different measurements is generic and holds for various interaction gates.
Conclusions:
- Measurements on the memory part provide a powerful tool to control and characterize quantum system dynamics.
- The choice of measurement strategy significantly impacts the emergent properties of the quantum system, such as its purity.
- The findings are robust across different interaction types and extend to continuous time models.
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