Related Experiment Video
Updated: Dec 6, 2025
09:23
Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
14.9K
Fundamental Limit of Phase Coherence in Two-Component Bose-Einstein Condensates.
Yifan Li1,2, Krzysztof Pawłowski3, Boris Décamps1
1Department of Physics, University of Basel, 4056 Basel, Switzerland.
Physical Review Letters
|October 5, 2020
Summary
We studied phase coherence in Bose-Einstein condensates of Rubidium-87 atoms. Coherence is limited by atom loss and collisions, but can be improved by lowering condensate density.
Area of Science:
- Atomic physics
- Quantum optics
- Condensed matter physics
Background:
- Bose-Einstein condensates (BECs) are crucial for quantum technologies.
- Maintaining phase coherence in multi-component BECs is challenging.
- Atom chip devices offer precise control over ultracold atoms.
Purpose of the Study:
- To experimentally and theoretically investigate phase coherence decay in two-component BECs.
- To identify the primary decoherence mechanisms affecting coherence.
- To explore methods for enhancing coherence in atom chip systems.
Main Methods:
- Utilized Ramsey interferometry to measure coherence decay.
- Employed a quantum trajectory method based on a master equation.
- Studied ^{87}Rb atoms in specific hyperfine ground states (|F=1,m_{F}=-1⟩ and |F=2,m_{F}=+1⟩).
Main Results:
- Phase coherence is limited by random collisional phase shifts from atom loss.
- The quantum trajectory model quantitatively confirms the observed decoherence mechanism.
- Reducing condensate density effectively slows down the decoherence process.
Conclusions:
- Collisional phase shifts due to atom loss are the dominant decoherence source.
- Quantum trajectory simulations accurately model decoherence in such systems.
- Findings are vital for advancing quantum metrology, entanglement, and chip-based atomic clocks.
Related Concept Videos
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.3K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.3K
04:08The Uncertainty Principle
30.4K
Werner Heisenberg considered the limits of how accurately one can measure properties of an electron or other microscopic particles. He determined that there is a fundamental limit to how accurately one can measure both a particle’s position and its momentum simultaneously. The more accurate the measurement of the momentum of a particle is known, the less accurate the position at that time is known and vice versa. This is what is now called the Heisenberg uncertainty principle. He...
30.4K
02:39Phase Transitions: Vaporization and Condensation
20.2K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
20.2K
02:31Phase Transitions
22.0K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
22.0K
01:18First Law: Particles in Two-dimensional Equilibrium
12.7K
Recall that a particle in equilibrium is one for which the external forces are balanced. Static equilibrium involves objects at rest, and dynamic equilibrium involves objects in motion without acceleration; but it is important to remember that these conditions are relative. For instance, an object may be at rest when viewed from one frame of reference, but that same object would appear to be in motion when viewed by someone moving at a constant velocity.
Newton's first law tells us about...
Newton's first law tells us about...
12.7K
01:10First Law: Particles in One-dimensional Equilibrium
7.7K
Newton's first law of motion states that a body at rest remains at rest, or if in motion, remains in motion at constant velocity, unless acted on by a net external force. It also states that there must be a cause for any change in velocity (a change in either magnitude or direction) to occur. This cause is a net external force. For example, consider what happens to an object sliding along a rough horizontal surface. The object quickly grinds to a halt, due to the net force of friction. If...
7.7K