A1 Refereed original research article in a scientific journal
Identical spin rotation effect and electron spin waves in quantum gas of atomic hydrogen
Authors: Lehtonen L, Vainio O, Ahokas J, Jarvinen J, Novotny S, Sheludyakov S, Suominen KA, Vasiliev S, Khmelenko VV, Lee DM
Publisher: IOP PUBLISHING LTD
Publication year: 2018
Journal: New Journal of Physics
Journal name in source: NEW JOURNAL OF PHYSICS
Journal acronym: NEW J PHYS
Article number: ARTN 055010
Volume: 20
Number of pages: 18
ISSN: 1367-2630
eISSN: 1367-2630
DOI: https://doi.org/10.1088/1367-2630/aac2ab
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/32085525
We present an experimental study of electron spin waves in atomic hydrogen gas compressed to high densities of similar to 5 x 10(18) cm(-3) at temperatures ranging from 0.26 to 0.6 K in the strong magnet ic field of 4.6 T. Hydrogen gas is in a quantum regime when the thermal de-Broglie wavelength is much larger than the s-wave scattering length. In this regime the identical particle effects play a major role in atomic collisions and lead to the identical spin rotation effect (ISR). We observed a variety of spin wave modes caused by this effect with strong dependence on the magnetic potential caused by variations of the polarizing magnetic field. We demonstrate confinement of the ISR modes in the magnetic potential and manipulate their properties by changing the spatial profile of the magnetic field. We have found that at a high enough density of H gas the magnons accumulate in their ground state in the magnetic trap and exhibit long coherence, which has a profound effect on the electron spin resonance spectra. Such macroscopic accumulation of the ground state occurs at a certain critical density of hydrogen gas, where the chemical potential of the magnons becomes equal to the energy of their ground state in the trapping potential.
Downloadable publication This is an electronic reprint of the original article. |  |
