Related Experiment Video
Updated: Jun 15, 2025
11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
7.4K
Improved memory truncation scheme for quasi-adiabatic propagator path integral via influence functional
Limin Liu1, Jiajun Ren1, Weihai Fang1
1Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, 100875 Beijing, People's Republic of China.
The Journal of Chemical Physics
|August 22, 2024
Summary
This study introduces a new memory truncation for the iterative quasi-adiabatic propagator path integral (iQuAPI) method. It improves accuracy in simulating non-Markovian quantum dynamics, especially for systems with long memory times.
Area of Science:
- Quantum mechanics
- Computational physics
- Quantum information science
Background:
- Simulating non-Markovian quantum dynamics in system-bath coupled problems is computationally demanding.
- Existing iterative quasi-adiabatic propagator path integral (iQuAPI) methods face challenges with long memory times due to conventional memory truncation.
Purpose of the Study:
- To develop and validate a novel memory truncation scheme for the iQuAPI method.
- To enhance the accuracy and efficiency of simulating quantum dynamics in systems with long memory times.
Main Methods:
- A new memory truncation scheme is proposed for the iQuAPI method.
- The scheme selectively retains significant parts of the influence functional using the density matrix renormalization group algorithm.
- Simulations were performed on the spin-boson model across various parameter sets.
Main Results:
- The novel memory truncation scheme demonstrates improved accuracy compared to conventional methods.
- Faster convergence was observed in simulations using the new scheme.
- The method effectively handles problems with long memory times.
Conclusions:
- The proposed memory truncation scheme significantly advances the capabilities of iQuAPI for simulating complex quantum systems.
- This approach offers a more accurate and efficient way to study non-Markovian quantum dynamics.
Related Concept Videos
01:18Adiabatic Processes for an Ideal Gas
3.0K
When an ideal gas is compressed adiabatically, that is, without adding heat, work is done on it, and its temperature increases. In an adiabatic expansion, the gas does work, and its temperature drops. Adiabatic compressions actually occur in the cylinders of a car, where the compressions of the gas-air mixture take place so quickly that there is no time for the mixture to exchange heat with its environment. Nevertheless, because work is done on the mixture during the compression, its...
3.0K
01:23Propagation of Action Potentials
5.4K
The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron.
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
5.4K
00:49Impulse-Momentum Theorem
11.3K
The total change in the motion of an object is proportional to the total force vector acting on it and the time over which it acts. This product is called impulse, a vector quantity with the same direction as the total force acting on the object.
By writing Newton's second law of motion in terms of the momentum of an object and the external force acting on it, and simultaneously using the definition of the impulse vector, it can be shown that the total impulse on an object is equal to its...
By writing Newton's second law of motion in terms of the momentum of an object and the external force acting on it, and simultaneously using the definition of the impulse vector, it can be shown that the total impulse on an object is equal to its...
11.3K
01:21Path Between Thermodynamics States
3.1K
Consider the two thermodynamic processes involving an ideal gas that are represented by paths AC and ABC in Figure 1:
3.1K
01:12Fermi Level Dynamics
228
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
228
01:26Thermodynamic Potentials
789
Thermodynamic potentials are state functions that are extremely useful in analyzing a thermodynamic system. They have dimensions of energy. The four important thermodynamic potentials are internal energy, enthalpy, Helmholtz free energy, and Gibbs free energy. These thermodynamic potentials can be expressed using two of the following variables: pressure, volume, temperature, and entropy. These two variables are expressed as the rate of change of the thermodynamic potential with respect to other...
789