Related Experiment Video
Updated: Aug 6, 2026
11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
Light transport in cold atoms and thermal decoherence
G Labeyrie1, D Delande, R Kaiser
1Institut Non Linéaire de Nice, UMR 6618 CNRS, 1361 route des Lucioles, F-06560 Valbonne, France. Guillaume.Labeyrie@inln.cnrs.fr
Physical Review Letters
|August 16, 2006
Summary
Atomic motion in cold vapors significantly disrupts light transport, causing a dramatic decrease in interference contrast as temperature rises. This highlights motion-induced decoherence
Area of Science:
- Atomic, Molecular, and Optical Physics
- Quantum Optics
- Condensed Matter Physics
Background:
- Coherent transport of light in atomic systems is sensitive to scattering processes.
- Understanding decoherence mechanisms is crucial for quantum technologies.
- Residual atomic motion can impact light propagation and interference.
Purpose of the Study:
- To experimentally and theoretically investigate the effect of atomic motion on coherent light transport in cold atomic vapors.
- To quantify the impact of temperature-induced atomic motion on coherent backscattering interference.
- To derive analytical expressions for coherence time in the presence of atomic motion.
Main Methods:
- Utilizing the coherent backscattering interference effect.
- Conducting experiments with cold atomic vapors at varying temperatures.
- Developing theoretical models to analyze light transport and decoherence.
- Deriving analytical expressions for coherence time.
Main Results:
- A dramatic decrease in interference contrast was observed as the temperature of the atomic cloud increased.
- Residual atomic motion was identified as a significant factor causing decoherence.
- The effect of motion-induced decoherence was confirmed even in the sub-Doppler temperature regime.
Conclusions:
- Atomic motion in cold vapors significantly degrades coherent light transport.
- Motion-induced decoherence is a critical factor affecting resonant scatterers, even at low temperatures.
- The study provides analytical tools to understand and predict coherence times in such systems.
Related Concept Videos
01:27Atomic Spectroscopy: Effects of Temperature
Atomization, converting samples into gas-phase atoms and ions, is essential for atomic spectroscopy. The flame temperature required for atomization affects the efficiency of the atomic spectroscopic methods by increasing the atomization efficiency and the relative population of the excited and ground states.
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
02:32The de Broglie Wavelength
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
01:23Atomic Nuclei: Nuclear Relaxation Processes
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis. This...
01:28Atomic Nuclei: Types of Nuclear Relaxation
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 energy to a nearby...
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 energy to a nearby...
01:11Atomic Nuclei: Larmor Precession Frequency
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession, and the angular frequency...
02:45The Quantum-Mechanical Model of an Atom
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. Schrödinger...