Related Experiment Video
Updated: Feb 10, 2026

10:16
Production and Targeting of Monovalent Quantum Dots
Published on: October 23, 2014
26.1K
Mean field dynamics of some open quantum systems
Marco Merkli1, Alireza Rafiyi1
1Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada A1C 5S7.
Summary
This study develops a new expansion for quantum system averages, analyzing observable dynamics for large particle numbers. The findings are applicable to quantum optics and energy-conserving models.
Area of Science:
- Quantum mechanics
- Statistical physics
Background:
- Understanding the behavior of large quantum systems interacting with a reservoir is crucial.
- Mean-field interactions simplify complex many-body quantum dynamics.
Purpose of the Study:
- To derive an expansion for averages of observables in quantum systems with mean-field interactions.
- To analyze the dynamics of these observables in the limit of large particle numbers.
Main Methods:
- Utilizing the Dyson series expansion of the propagator.
- Analyzing the system in the limit of large N (number of particles).
Main Results:
- An expansion for averages of observables (both particles and reservoir) in inverse powers of N.
- Detailed analysis of the dynamics of n-particle observables, extensive observables, fluctuations, and reservoir observables.
Conclusions:
- The derived expansion provides a powerful tool for studying large quantum systems.
- The results are illustrated using the infinite mode Dicke model and energy-conserving models.
Related Concept Videos
Quantum Numbers
52.1K
It is said that the energy of an electron in an atom is quantized; that is, it can be equal only to certain specific values and can jump from one energy level to another but not transition smoothly or stay between these levels.
52.1K
The Quantum-Mechanical Model of an Atom
59.5K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
59.5K
Second Order systems II
412
In an underdamped second-order system, where the damping ratio ζ is between 0 and 1, a unit-step input results in a transfer function that, when transformed using the inverse Laplace method, reveals the output response. The output exhibits a damped sinusoidal oscillation, and the difference between the input and output is termed the error signal. This error signal also demonstrates damped oscillatory behavior. Eventually, as the system reaches a steady state, the error diminishes to zero.
412
Dynamic Equilibrium
63.3K
A reversible chemical reaction represents a chemical process that proceeds in both forward (left to right) and reverse (right to left) directions. When the rates of the forward and reverse reactions are equal, the concentrations of the reactant and product species remain constant over time and the system is at equilibrium. A special double arrow is used to emphasize the reversible nature of the reaction. The relative concentrations of reactants and products in equilibrium systems vary greatly;...
63.3K
First Order Systems
434
First-order systems, such as RC circuits, are foundational in understanding dynamic systems due to their straightforward input-output relationship. Analyzing their responses to different input functions under zero initial conditions reveals significant insights into system behavior.
When a first-order system is subjected to a unit-step input, its response is characterized by its transfer function. By applying the Laplace transform of the unit-step input to the transfer function, expanding the...
When a first-order system is subjected to a unit-step input, its response is characterized by its transfer function. By applying the Laplace transform of the unit-step input to the transfer function, expanding the...
434
Second Order systems I
616
A servo system exemplifies a second-order system, featuring a proportional controller and load elements that ensure the output position aligns with the input position. The relationship between these components is described by a second-order differential equation. Applying the Laplace transform under zero initial conditions yields the transfer function, showing how inputs are converted to outputs in the system.
By reinterpreting the system, one can derive the closed-loop transfer function, which...
By reinterpreting the system, one can derive the closed-loop transfer function, which...
616

