Dynamics of a single vortex line in a Bose-Einstein condensate

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Fluids and Gases

Background:

• Bose-Einstein condensates (BECs) are quantum states of matter formed by cooling bosons to near absolute zero.
• Quantized vortices are topological defects that can form in rotating superfluids like BECs.

Purpose of the Study:

• To experimentally investigate the behavior and properties of a single quantized vortex line in a rotating prolate Bose-Einstein condensate.
• To measure the vortex line's length, survival time, and spatial deviation as a function of time and temperature.

Main Methods:

• Utilized a rotating prolate Bose-Einstein condensate confined by a harmonic potential.
• Employed experimental techniques to monitor the vortex line as it leaves the condensate.
• Measured the length of the vortex line over time and at different temperatures.

Main Results:

• Observed that the vortex line is predominantly curved at its ends, consistent with theoretical predictions.
• Measured vortex line survival times up to 10 seconds at low temperatures.
• Found a correlation between the vortex line's length, its deviation from the trap center, and the angular momentum per particle.

Conclusions:

• The experimental results support theoretical models of quantized vortices in Bose-Einstein condensates.
• The study provides insights into the dynamics and stability of vortex lines in quantum fluids.
• Quantified the relationship between vortex line geometry and the condensate's angular momentum.