Related Experiment Video
Updated: Sep 29, 2025
11:11
Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation
Published on: May 2, 2016
11.2K
Equilibration and "Thermalization" in the Adapted Caldeira-Leggett Model
1Center for Quantum Mathematics and Physics, University of California at Davis, One Shields Ave., Davis, CA 95616, USA.
Entropy (Basel, Switzerland)
|March 25, 2022
Summary
This study investigates equilibration in a quantum toy model, showing dephasing enables it. Primitive thermalization aspects appear, hinting at ergodic behavior in larger systems.
Area of Science:
- Quantum mechanics
- Statistical mechanics
- Condensed matter physics
Background:
- Quantum decoherence is crucial for understanding the transition from quantum to classical systems.
- The Adapted Caldeira-Leggett (ACL) model provides a tractable framework for studying quantum-environment interactions.
Purpose of the Study:
- To explore equilibration processes in the ACL model.
- To investigate the role of dephasing in achieving equilibration.
- To identify conditions for primitive thermalization and links to ergodicity.
Main Methods:
- Numerical studies using the ACL toy model.
- Analysis of quantum decoherence and dephasing effects.
- Examination of global energy eigenstates and their properties.
Main Results:
- Dephasing was shown to facilitate equilibration across various scenarios.
- Primitive aspects of thermalization were observed for specific parameter choices.
- Observed phenomena were linked to the properties of global energy eigenstates.
Conclusions:
- The ACL model demonstrates how dephasing drives equilibration.
- While full thermalization is limited by model constraints, partial thermalization is achievable.
- The findings suggest potential mechanisms for ergodicity in more complex quantum systems.
Related Concept Videos
01:11Temperature and Thermal Equilibrium
7.5K
Heat and temperature are essential concepts for everyone every day. The study of heat and temperature is part of an area of physics known as thermodynamics. It is not always easy to distinguish heat and temperature.
The concept of temperature has evolved from the common concepts of hot and cold. The scientific definition of temperature explains more than just our sense of hot and cold. Temperature is operationally defined as the quantity measured with a thermometer. Furthermore, temperature is...
The concept of temperature has evolved from the common concepts of hot and cold. The scientific definition of temperature explains more than just our sense of hot and cold. Temperature is operationally defined as the quantity measured with a thermometer. Furthermore, temperature is...
7.5K
01:27Thermal expansion and Thermal stress: Problem Solving
1.4K
San Francisco's Golden Gate Bridge is exposed to temperatures ranging from -15 °C to 40 °C. At its coldest, the main span of the bridge is 1275 m long. Assuming that the bridge is made entirely of steel, what is the change in its length between these temperatures?
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in...
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in...
1.4K
01:19Calorimetry
3.3K
When objects at different temperatures are placed in contact with each other but isolated from everything else, they attain thermal equilibrium. A container that prevents heat transfer in or out is called a calorimeter, and the use of a calorimeter to make measurements is called calorimetry. Generally, these measurements involve heat or specific heat capacity. The term "calorimetry problem" is used for any problem where the specified objects are thermally isolated from their...
3.3K
01:16Thermal Sigmatropic Reactions: Overview
2.2K
Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
2.2K
02:41Constant Volume Calorimetry
28.5K
Calorimeters are useful to determine the heat released or absorbed by a chemical reaction. Coffee cup calorimeters are designed to operate at constant (atmospheric) pressure and are convenient to measure heat flow (or enthalpy change) accompanying processes that occur in solution at constant pressure. A different type of calorimeter that operates at constant volume, colloquially known as a bomb calorimeter, is used to measure the energy produced by reactions that yield large amounts of heat and...
28.5K
01:12Temperature Dependent Deformation
205
In a nonhomogeneous rod made up of steel and brass, restrained at both ends and subjected to a temperature change, several steps are involved in calculating the stress and compressive load. Due to the problem's static indeterminacy, one end support is disconnected, allowing the rod to experience the temperature change freely. Next, an unknown force is applied at the free end, triggering deformations in the rod's steel and brass portions. These deformations are then calculated and added...
205