Finite-bath open quantum systems: Exact dynamics

Area of Science:

• Quantum physics
• Open quantum systems
• Quantum information theory

Background:

• Open quantum systems are crucial for understanding quantum phenomena.
• Deriving exact master equations for complex systems remains a challenge.
• The principle of minimal dissipation offers a novel approach.

Purpose of the Study:

• To develop a method for deriving exact master equations from dynamical maps for finite open quantum systems.
• To investigate the dynamics of the central spin model under different interaction types.
• To explore the thermodynamic performance of derived quantum systems as quantum batteries.

Main Methods:

• Utilizing the principle of minimal dissipation to derive exact master equations.
• Analyzing the central spin model with Heisenberg and stochastic pure-dephasing interactions.
• Deriving closed-form master equations for both interaction models.

Main Results:

• A novel phase-covariant quantum channel is identified for Heisenberg interactions in the strong-coupling regime.
• The stochastic pure-dephasing interaction leads to a microscopic derivation of the random telegraph noise (RTN) channel.
• Closed-form master equations for both models were successfully derived.
• Quantum batteries based on RTN demonstrate advantages in charge storage and reveal a direct relationship between quantum heat current and charging power.

Conclusions:

• The developed method provides exact master equations for open quantum systems.
• The study establishes a quantum foundation for the RTN channel and offers insights into stochastic couplings.
• The findings open new avenues for quantum information protocols and quantum battery research.