A cryogenic chamber setup for superfluid helium experiments with optical fiber and electrical access

Area of Science:

• Quantum Many-Body Physics
• Low-Temperature Physics
• Nanophotonics

Background:

• Superfluid helium is a quantum liquid vital for studying many-body physics.
• Its unique mechanical and optical properties make it promising for dark matter detection, gravitational wave detection, and quantum computation.
• Current experiments face high entry barriers due to complex cryogenic setups.

Purpose of the Study:

• To design and construct a versatile helium chamber for millikelvin operation within a dilution refrigerator.
• To enable precise control over superfluid helium thin films for applications like optomechanics.
• To provide a adaptable platform for diverse superfluid helium research.

Main Methods:

• Construction of a helium chamber with electrical and optical fiber access for dilution refrigerators.
• Integration of an automated gas handling system for precise helium gas control.
• Utilizing silicon nanophotonic resonators to monitor and tune superfluid helium film thickness on a sub-nanometer scale.

Main Results:

• Demonstrated precise, in situ control and tuning of superfluid helium film thickness.
• Achieved optomechanically induced phonon lasing of third sound modes in superfluid helium films.
• Showcased the dependence of the lasing threshold on superfluid film thickness.

Conclusions:

• The developed cryogenic chamber offers a versatile platform for superfluid helium research.
• Precise thin-film control opens new avenues for superfluid thin film optomechanics.
• The setup facilitates advancements in fundamental and applied research utilizing superfluid helium's quantum properties.