Flux rectification in the quantum XXZ chain

Area of Science:

• Quantum physics
• Condensed matter physics
• Statistical mechanics

Background:

• Thermal rectification, the direction-dependent heat flux, is key for developing thermal diodes.
• Quantum spin chains offer a platform to explore fundamental physical phenomena like thermal transport.

Purpose of the Study:

• To investigate thermal rectification in a quantum XXZ chain under an inhomogeneous field.
• To analyze the system's non-equilibrium dynamics driven by boundary reservoirs.
• To determine the dependence of the rectification coefficient on model parameters.

Main Methods:

• Modeling the quantum XXZ chain with an inhomogeneous field using a Lindblad master equation.
• Exact treatment for small system sizes and numerical analysis for larger systems.
• Investigating the functional dependence of the rectification coefficient on anisotropy, field amplitude, and driving strength.

Main Results:

• An explicit expression for the rectification coefficient was derived near the XX point under specific conditions (small inhomogeneity, low driving).
• The study demonstrates that thermal rectification persists even in the thermodynamic limit.
• It was proven that no rectification occurs in the standard XX chain.

Conclusions:

• The quantum XXZ chain exhibits tunable thermal rectification, with potential applications in thermal management.
• The findings provide a theoretical framework for understanding non-equilibrium quantum transport phenomena.
• The persistence of rectification in the thermodynamic limit highlights its robustness and practical relevance.