Supersonic Rotation of a Superfluid: A Long-Lived Dynamical Ring

Area of Science:

• Quantum physics
• Condensed matter physics

Background:

• Superfluidity is a quantum mechanical phenomenon where a fluid flows without friction.
• Creating and sustaining long-lived superfluid states is crucial for fundamental physics research and potential applications.

Purpose of the Study:

• To experimentally realize a long-lived superfluid flow in a rotating quantum gas.
• To investigate the dynamics and properties of a superfluid ring sustained by angular momentum.

Main Methods:

• Utilizing a quantum gas confined in an anharmonic potential.
• Inducing rotation via an elliptical deformation of the trapping potential.
• Employing angular-momentum-selective evaporation to accelerate rotation.

Main Results:

• Achieved a stable, long-lived superfluid flow sustained by the gas's own angular momentum.
• Created a dynamical ring with approximately 350ℏ angular momentum per particle.
• Observed a quasi-two-dimensional superfluid density profile with velocities reaching Mach 18.
• Maintained the superfluid rotation for over one minute.

Conclusions:

• Demonstrated the experimental feasibility of creating persistent superfluid flow in rotating quantum gases.
• The study provides insights into the dynamics of angular momentum in quantum fluids.
• Highlights the potential for creating robust quantum states in anharmonic potentials.