Abstract
We report on the magnetic trapping of an ultracold ensemble of atoms close to a superconducting ring prepared in different states of quantized magnetic flux. The niobium ring of radius is prepared in a flux state , where is the flux quantum and varying between . An atomic cloud of 250 nK temperature is positioned with a harmonic magnetic trapping potential at distance below the ring. The inhomogeneous magnetic field of the supercurrent in the ring contributes to the magnetic trapping potential of the cloud. The induced deformation of the magnetic trap impacts the shape of the cloud, the number of trapped atoms, as well as the center-of-mass oscillation frequency of Bose-Einstein condensates. When the field applied during cooldown of the chip is varied, the change of these properties shows discrete steps that quantitatively match flux quantization.
- Received 4 September 2014
DOI:https://doi.org/10.1103/PhysRevLett.114.113003
© 2015 American Physical Society
Synopsis
Cold Atoms, Meet Flux Quanta
Published 17 March 2015
A cloud of atoms trapped close to a superconducting ring can detect the magnetic field inside the ring with single-quantum sensitivity.
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