Numerical approach to time-dependent quantum transport and dynamical Kondo transition

Area of Science:

• Quantum physics
• Computational chemistry
• Condensed matter theory

Background:

• Simulating open quantum systems at low temperatures presents significant computational challenges.
• Existing methods often struggle with accuracy and efficiency in the low-temperature regime.
• Understanding transient electronic dynamics is crucial for developing quantum technologies.

Purpose of the Study:

• To develop an accurate and efficient numerical approach for simulating transient electronic dynamics in open quantum systems at low temperatures.
• To improve the computational feasibility of studying complex quantum phenomena like Kondo effects.
• To provide a versatile method applicable to various reservoir spectral functions.

Main Methods:

• A hybrid scheme combining Matsubara expansion and frequency dispersion treatment.
• Utilizing formally exact hierarchical equations of motion quantum dissipation theory.
• Developing a method to efficiently compute reservoir correlation functions.

Main Results:

• The proposed hybrid scheme significantly reduces computational cost, especially at low temperatures.
• Accurate simulation of dynamical Kondo effects was achieved.
• Cotunneling-induced Kondo transitions were resolved in transient currents under time-dependent voltages.

Conclusions:

• The developed numerical approach offers an accurate and efficient solution for low-temperature open quantum system dynamics.
• The method successfully captures complex quantum phenomena, including Kondo effects and transitions.
• This work provides a valuable tool for theoretical investigations in quantum electronics and materials science.