Superfluid

Temperature induced decay of persistent currents in superfluid ultracold gas

We study how temperature affects the lifetime of a quantized, persistent current state in a toroidal Bose-Einstein condensate. When the temperature is increased, we find a decrease in the persistent current lifetime. Comparing our measured decay …

Subwavelength-width optical tunnel junctions for ultracold atoms

We propose a new method for creating far-field optical barrier potentials for ultracold atoms with widths that are narrower than the diffraction limit and can approach tens of nanometers. The reduced widths stem from the nonlinear atomic response to …

Self-heterodyne detection of the in situ phase of an atomic superconducting quantum interference device

We present theoretical and experimental analysis of an interferometric measurement of the in situ phase drop across and current flow through a rotating barrier in a toroidal Bose-Einstein condensate (BEC). This experiment is the atomic analog of the …

Interferometric Measurement of the Current-Phase Relationship of a Superfluid Weak Link

Weak connections between superconductors or superfluids can differ from classical links due to quantum coherence, which allows flow without resistance. Transport properties through such weak links can be described with a single function, the …

Resistive Flow in a Weakly Interacting Bose-Einstein Condensate

We report the direct observation of resistive flow through a weak link in a weakly interacting atomic Bose-Einstein condensate. Two weak links separate our ring-shaped superfluid atomtronic circuit into two distinct regions, a source and a drain. …

Hysteresis in a quantized superfluid 'atomtronic' circuit

Atomtronics is an emerging interdisciplinary field that seeks to develop new functional methods by creating devices and circuits where ultracold atoms, often superfluids, have a role analogous to that of electrons in electronics. Hysteresis is widely …