Transport and thermodynamics in quantum junctions: A scattering approach

Area of Science:

• Quantum physics
• Condensed matter physics
• Thermodynamics

Background:

• Standard non-equilibrium Green's function methods are used for quantum transport.
• Recent studies explored quantum thermodynamics in slowly driven systems.
• Understanding quantum systems coupled to multiple thermal environments is crucial.

Purpose of the Study:

• To present a novel scattering approach for quantum transport and thermodynamics.
• To extend existing formalisms to systems with multiple thermal baths and strong coupling.
• To derive new expressions for non-equilibrium steady states and energy dissipation.

Main Methods:

• Developed a scattering approach based on quantum system-environment interactions.
• Derived general expressions for the non-equilibrium steady-state density matrix.
• Obtained a general expression for dissipated power for driven systems without wide-band approximation.
• Validated the symmetric splitting of system-bath interactions for multiple baths.
• Demonstrated equivalence to Landauer-Buttiker formalism and its extensions.

Main Results:

• Derived a general explicit expression for the non-equilibrium steady-state density matrix for multi-bath systems.
• Obtained a general expression for dissipated power for a driven resonant level, considering changing energy levels and couplings.
• Confirmed the validity of symmetric splitting for multi-bath interactions.
• Showed the equivalence of the scattering approach to established transport formalisms.
• Generalized entropy production expressions to multi-bath driven systems.

Conclusions:

• The scattering approach provides a unified framework for quantum transport and thermodynamics.
• The method accurately describes systems under strong coupling to multiple thermal environments.
• New results offer deeper understanding of non-equilibrium phenomena and energy dissipation in quantum systems.