Polaron transformed canonically consistent quantum master equation

Area of Science:

• Quantum Physics
• Condensed Matter Theory
• Theoretical Chemistry

Background:

• Accurately describing large, strongly interacting quantum many-body systems in open quantum systems is a significant theoretical challenge.
• Existing methods often struggle with strong system-bath interactions, limiting the scope of study.
• The canonically consistent quantum master equation (CCQME) offers a way to extend beyond weak-coupling approximations.

Purpose of the Study:

• To develop a theoretical framework for open quantum systems that can handle strong system-bath interactions.
• To enhance the capabilities of the CCQME by incorporating a polaron transformation.
• To enable the study of larger quantum systems and stronger interaction regimes.

Main Methods:

• Formulation of a polaron-transformed version of the canonically consistent quantum master equation (CCQME).
• Unified and transparent derivation combining polaron transformation with CCQME.
• Application to the spin-boson model for validation.

Main Results:

• The polaron-transformed CCQME successfully extends the accessible system-bath interaction strengths into the ultra-strong regime.
• The method demonstrates excellent agreement with numerically exact simulations (time-evolving matrix product operator).
• A prediction of initial-state-independent slowing down of thermalization in the strong-coupling regime of the spin-boson model.

Conclusions:

• The polaron-transformed CCQME is a powerful tool for studying open quantum systems with strong interactions.
• This advancement allows for the investigation of previously inaccessible regimes in quantum many-body physics.
• The findings pave the way for deeper understanding of thermalization dynamics in strongly coupled quantum systems.