Efficient Simulation of Finite-Temperature Open Quantum Systems

Area of Science:

• Quantum physics
• Computational chemistry
• Condensed matter physics

Background:

• Chain-mapping and time-dependent density matrix renormalization group are used for open-system quantum dynamics.
• Current methods face challenges with computational scaling at higher temperatures.

Purpose of the Study:

• To develop a more efficient method for simulating open quantum systems at finite temperatures.
• To overcome the limitations of existing computational approaches.

Main Methods:

• Nonperturbative description of system dynamics using temperature-dependent system-environmental couplings.
• Utilizing the initial environment state as a pure vacuum state instead of a mixed thermal state.

Main Results:

• The global system-environment state remains pure if the initial system state is pure.
• Achieved significant speed-up in simulations.
• Reduced memory requirements for computations.

Conclusions:

• This approach enables efficient simulation of open quantum systems across all temperature ranges.
• Applicable to quantum thermodynamics and mesoscopic quantum phenomena.
• Provides a powerful tool for studying complex quantum systems.