Related Experiment Video
Updated: Jul 7, 2026
10:00
Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
Collective atomic recoil lasing with a partially coherent pump.
1Scottish Universities Physics Alliance (SUPA), Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG, United Kingdom.
Physical Review Letters
|February 1, 2008
Summary
Pump phase noise in atomic gases reduces backscattered light growth rate but can increase intensity. This highlights noise
Area of Science:
- Atomic physics
- Quantum optics
- Many-body systems
Background:
- Collective backscattering of light in atomic gases is a key quantum optical phenomenon.
- Understanding the influence of pump field properties, such as coherence, is crucial for controlling light-matter interactions.
Purpose of the Study:
- To investigate the impact of pump phase noise on collective light backscattering in cold, collisionless atomic gases.
- To analyze how partial coherence of the pump field affects the dynamics of backscattered light.
Main Methods:
- Theoretical investigation of light-matter interactions in a many-body atomic system.
- Modeling the effect of a partially coherent pump field on collective backscattering dynamics.
Main Results:
- Pump phase noise reduces the growth rate of the backscattered field compared to a coherent pump.
- Despite reduced growth rate, the overall backscattered light intensity can be enhanced under partial coherence.
- Demonstration of noise playing a counterintuitive role in nonlocally coupled systems.
Conclusions:
- Phase noise in pump fields can modify collective backscattering in atomic gases.
- Partial coherence offers a route to potentially enhance backscattered light intensity.
- Findings underscore the complex and often counterintuitive role of noise in quantum many-body phenomena.
Related Concept Videos
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...
01:11Atomic 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...
01:05Atomic Nuclei: Magnetic Resonance
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
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...
01:12Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
01:03Atomic Nuclei: Nuclear Spin State Overview
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...