Superfluidity versus Bloch oscillations in confined atomic gases

Area of Science:

• Quantum physics
• Condensed matter physics
• Ultracold atomic gases

Background:

• Superfluidity in one-dimensional (1D) systems is sensitive to quantum fluctuations and geometry.
• Understanding phase slip nucleation is crucial for characterizing superfluid response.

Purpose of the Study:

• To investigate the superfluid properties of 1D bosonic systems in finite geometries.
• To analyze the impact of quantum fluctuations and particle quantization on phase slip nucleation.

Main Methods:

• Utilizing instanton techniques to calculate the phase slip nucleation rate.
• Simulating bosonic atom gases/liquids in confined trap geometries (ring and tube).
• Analyzing the chemical potential response to a moving defect.

Main Results:

• Phase slip nucleation is suppressed in a ring geometry, preserving superfluidity.
• Phase slips proliferate in a tube geometry, leading to observable Bloch oscillations.
• Bloch oscillations in the chemical potential demonstrate individual atom tunneling, a consequence of quantization.

Conclusions:

• The geometry of confinement dictates the superfluid response in 1D bosonic systems.
• Particle quantization fundamentally influences transport properties through defect-induced tunneling.
• This work provides insights into quantum fluctuations and superfluidity in low-dimensional systems.