Vortex gyroscope imaging of planar superfluids.

Area of Science:

• Quantum physics
• Atomic physics
• Condensed matter physics

Background:

• Bose-Einstein condensates (BECs) are quantum states of matter.
• Distinguishing vortices from antivortices in 2D BECs is crucial for understanding superfluidity.
• Current imaging methods often require multiple steps or complex analysis.

Purpose of the Study:

• To present a novel, robust imaging technique for differentiating vortices and antivortices in quasi-2D Bose-Einstein condensates.
• To enable the determination of vortex sign and location from a single density image.
• To facilitate experimental studies of 2D superfluid turbulence and associated phenomena.

Main Methods:

• Excitation of a generalized gyroscopic mode by tilting the planar condensate.
• Standard absorption imaging of the tilted condensate.
• Analysis of the resulting density image to identify vortex/antivortex characteristics.

Main Results:

• A single absorption image of the atom density is sufficient to distinguish vortices from antivortices.
• The technique accurately reveals the sign and precise location of each vortex.
• The method is robust and applicable to quasi-two-dimensional Bose-Einstein condensates.

Conclusions:

• The proposed imaging technique offers a simplified and effective way to study quantized vortices in BECs.
• This method is expected to enable measurements of the incompressible kinetic energy spectrum.
• It paves the way for observing negative-temperature phase transitions in vortex gases driven by 2D superfluid turbulence.