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Dimension reduction by balanced truncation: application to light-induced control of open quantum systems
Boris Schäfer-Bung1, Carsten Hartmann, Burkhard Schmidt
1Institut für Mathematik, Freie Universität Berlin, Arnimallee 6, D-14195 Berlin, Germany. boris.schaefer-bung@fu-berlin.de
Balanced truncation effectively reduces the complexity of open quantum systems. This control method, applied to quantum dynamics, achieves significant dimension reduction based on system parameters.
Area of Science:
- Quantum Control
- Quantum Dynamics
- Control Theory
Background:
- Balanced truncation is a standard technique for reducing the state-space dimension in linear control systems.
- Open quantum systems are often modeled using the Liouville-von Neumann equation within the Lindblad formalism.
- Controlling quantum systems requires addressing bilinear terms arising from control field coupling.
Purpose of the Study:
- To apply balanced truncation for the first time to control open quantum systems.
- To generalize linear balanced truncation theory for bilinear quantum control.
- To investigate the accuracy and efficiency of dimension reduction in a specific quantum system.
Main Methods:
- Generalizing linear balanced truncation for bilinear terms in quantum systems.
- Modeling dissipative quantum dynamics using the Liouville-von Neumann equation and Lindblad formalism.
- Applying the method to a particle in an asymmetric double well potential driven by an external field.
Main Results:
- Demonstrated efficient dimension reduction for open quantum system control.
- Investigated the accuracy of the truncated model by comparing population dynamics.
- Showed that the degree of dimension reduction is dependent on temperature and relaxation rate.
Conclusions:
- Balanced truncation is a viable and effective technique for simplifying the control of open quantum systems.
- The generalized method accurately represents the system's dynamics after dimension reduction.
- System parameters like temperature and relaxation rate influence the efficiency of the reduction.
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