Related Experiment Video
Updated: Jun 12, 2025

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Universal structure of computing moments for exact quantum dynamics: Application to arbitrary system-bath couplings
Rui-Hao Bi1, Wei Liu1, Wenjie Dou1,2,3
1Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang 310024, China.
We present a new method for calculating higher-order moments in open quantum systems using Memory Kernel Coupling Theory (MKCT). This approach accurately models complex system-bath interactions, advancing quantum dynamics simulations.
Area of Science:
- Quantum Mechanics
- Theoretical Physics
- Chemical Physics
Background:
- Open quantum systems are crucial for understanding complex phenomena.
- Calculating higher-order moments of correlation functions is computationally challenging.
- Existing methods struggle with arbitrary system-bath couplings.
Purpose of the Study:
- To introduce a general procedure for computing higher-order moments in open quantum systems.
- To extend the Memory Kernel Coupling Theory (MKCT) for broader applicability.
- To demonstrate the method for polynomial system-bath couplings.
Main Methods:
- Developed a general procedure based on Memory Kernel Coupling Theory (MKCT).
- Analyzed recursive commutators of system operators, revealing a universal hierarchy.
- Evaluated system and bath operators separately, using a generating function for bath expectation values.
- Applied the method to the spin-boson model with linear and quadratic coupling.
Main Results:
- The recursive commutators of system operators follow a universal hierarchy for polynomial couplings.
- Higher-order moments can be computed by evaluating separate system and bath expectation values.
- The dipole autocorrelation function for the spin-boson model was accurately reproduced.
- Achieved agreement with the hierarchical equations of motion approach.
Conclusions:
- The generalized MKCT provides an accurate and efficient method for open quantum systems.
- The universal hierarchy of commutators simplifies calculations for complex couplings.
- This work offers a promising path for accurate dynamics in intricate quantum systems.
Related Concept Videos
The Quantum-Mechanical Model of an Atom
The de Broglie Wavelength
Equilibrium Conditions for a Particle
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
System of Forces and Couples
The principle of transmissibility plays a crucial role in this process. According to...
Symmetry in Maxwell's Equations
The Uncertainty Principle

