Related Experiment Video
Updated: May 22, 2025
11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
7.4K
Observing time-dependent energy level renormalisation in an ultrastrongly coupled open system
Alessandra Colla1,2, Florian Hasse3, Deviprasath Palani4
1Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, D-79104, Freiburg, Germany. alessandra.colla@unimi.it.
Nature Communications
|March 14, 2025
Summary
Strong coupling in open quantum systems causes significant energy shifts, impacting quantum technologies. This study experimentally confirms these dynamic shifts, validating a new quantum thermodynamics framework.
Area of Science:
- Quantum Physics
- Quantum Thermodynamics
- Open Quantum Systems
Background:
- Understanding strong coupling and memory effects in open quantum systems is crucial for controlling quantum states.
- Energy level shifts in quantum systems are fundamental to their behavior and applications.
Purpose of the Study:
- To experimentally investigate the influence of strong coupling and memory effects on energy levels in a two-level open quantum system.
- To validate the minimal-dissipation Ansatz as a predictive framework for these phenomena.
Main Methods:
- Utilizing Ramsey interferometry in a trapped ion system.
- Operating in the strong coupling regime with a single-mode quantum environment.
- Probing time-dependent energy shifts and dissipative effects.
Main Results:
- Observed significant time-dependent energy shifts (up to 15% of bare frequency) due to ultra-strong system-mode interactions.
- Identified these shifts as generalized Lamb shifts, consistent with time-averaged predictions.
- Provided experimental evidence supporting the minimal-dissipation Ansatz.
Conclusions:
- The minimal-dissipation Ansatz accurately predicts dynamic energy shifts in strongly coupled open quantum systems.
- These findings establish a foundation for quantum thermodynamics research and technology development.
- The experimental approach offers a benchmark for studying strong-coupling phenomena.
Related Concept Videos
01:12Fermi Level Dynamics
213
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...
213
03:25Free Energy Changes for Nonstandard States
10.8K
The free energy change for a process taking place with reactants and products present under nonstandard conditions (pressures other than 1 bar; concentrations other than 1 M) is related to the standard free energy change according to this equation:
where R is the gas constant (8.314 J/K·mol), T is the absolute temperature in kelvin, and Q is the reaction quotient. This equation may be used to predict the spontaneity of a process under any given set of conditions.
Reaction Quotient...
where R is the gas constant (8.314 J/K·mol), T is the absolute temperature in kelvin, and Q is the reaction quotient. This equation may be used to predict the spontaneity of a process under any given set of conditions.
Reaction Quotient...
10.8K
02:18The Bohr Model
50.2K
Following the work of Ernest Rutherford and his colleagues in the early twentieth century, the picture of atoms consisting of tiny dense nuclei surrounded by lighter and even tinier electrons continually moving about the nucleus was well established. This picture was called the planetary model since it pictured the atom as a miniature “solar system” with the electrons orbiting the nucleus like planets orbiting the sun. The simplest atom is hydrogen, consisting of a single proton as...
50.2K
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
909
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
909
01:10Energy Diagrams - II
4.6K
Energy diagrams are important to understand the dynamics of a system. The topology of an energy diagram helps illustrate the equilibrium points of the system.
The point in the energy diagram at which the system’s potential energy is the lowest is known as the local minima. The system tends to stay in this position indefinitely unless acted upon by a net force. The slope of the potential energy diagram at the local minima is zero, indicating that zero net force is acting on the system. The...
The point in the energy diagram at which the system’s potential energy is the lowest is known as the local minima. The system tends to stay in this position indefinitely unless acted upon by a net force. The slope of the potential energy diagram at the local minima is zero, indicating that zero net force is acting on the system. The...
4.6K
01:28Atomic Nuclei: Types of Nuclear Relaxation
234
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
234