Velocity-dependent quantum phase slips in 1D atomic superfluids

Velocity-dependent quantum phase slips in 1D atomic superfluids

Quantum phase slips are the primary excitations in one-dimensional superfluids and superconductors at low temperatures but their existence in ultracold quantum gases has not been demonstrated yet. We now study experimentally the nucleation rate of phase slips in one-dimensional superfluids realized with ultracold quantum gases, flowing along a periodic potential. We observe a crossover between ...

Quasiparticle scattering by quantum phase slips in one-dimensional superfluids.

Quantum phase slips (QPS) in narrow superfluid channels generate momentum by unwinding the supercurrent. In a uniform Bose gas, this momentum needs to be absorbed by quasiparticles (phonons). We show that this requirement results in an additional exponential suppression of the QPS rate (compared to the rate of QPS induced by a sharply localized perturbation). In BCS-paired fluids, momentum can ...

Quantum phase slips in superconducting nanowires.

We have measured the resistance vs temperature of more than 20 superconducting nanowires with nominal widths ranging from 10 to 22 nm and lengths from 100 nm to 1 microm. With decreasing cross-sectional areas, the wires display increasingly broad resistive transitions. The data are in very good agreement with a model that includes both thermally activated phase slips close to T(c) and quantum p...

Quantum phase slips in Josephson junction rings

G. Rastelli,1,2 I. M. Pop,3,4 and F. W. J. Hekking1 1Université Grenoble 1/CNRS, LPMMC UMR 5493, B.P. 166, 38042 Grenoble, France 2Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany 3Institut Néel, CNRS, and Université Joseph Fourier, B.P. 166, 38042 Grenoble, France 4Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA (Received 6 January 2012; rev...

Quantum phase slips in a confined geometry