Observation of ultracold atomic bubbles in orbital microgravity

Area of Science:

• Quantum physics
• Atomic physics
• Cold atom research

Background:

• Quantum system understanding advances through geometry and topology exploration.
• Confining atoms on an ellipsoidal surface presents novel geometric and topological challenges.
• Ultracold bubbles, potentially Bose-Einstein condensates, are relevant to quantized-vortex flow, collective modes, and expansion physics.

Purpose of the Study:

• To explore a heretofore unexplored geometry and topology using ultracold atoms confined on an ellipsoidal surface.
• To investigate the creation and properties of ultracold atom bubbles in microgravity.
• To study bubble thermodynamics, cooling during inflation, and shell structure dynamics.

Main Methods:

• Utilizing the NASA Cold Atom Lab facility on the International Space Station.
• Creating ultracold atom bubbles via a radiofrequency-dressing protocol.
• Observing bubble configurations, thermodynamics, and dynamics in perpetual freefall.

Main Results:

• Successfully created bubbles of ultracold atoms with varying sizes and temperatures.
• Observed substantial cooling associated with bubble inflation.
• Achieved partial bubble trap coverings with ultracold films and observed shell structure dynamics.

Conclusions:

• This work represents early measurements of ultracold atoms in space, enabling exploration of quantum systems difficult to create on Earth.
• The study demonstrates the feasibility of creating and studying ultracold atom bubbles in microgravity.
• Future research will focus on Bose-Einstein condensed bubbles, excitations, and topological effects in orbital microgravity.