Zobrazeno 1 - 10
of 947
pro vyhledávání: '"Suominen, K."'
Autor:
Lehtonen, L., Vainio, O., Ahokas, J., Järvinen, J., Sheludyakov, S., Suominen, K. -A., Vasiliev, S., Khmelenko, V., Lee, D. M.
Publikováno v:
Phys. Scr. 93 094002 (2018)
Our recent experimental work on electron spin waves in atomic hydrogen gas has prompted a revisit of the theory of the Identical Spin Rotation Effect (ISRE). A key characteristic determining the properties of the spin waves is the quality factor of I
Externí odkaz:
http://arxiv.org/abs/1804.10431
Autor:
Lehtonen, L., Vainio, O., Ahokas, J., Järvinen, J., Novotny, S., Sheludyakov, S., Suominen, K. -A., Vasiliev, S., Khmelenko, V., Lee, D. M.
Publikováno v:
New J. Phys. 20 055010 (2018)
We present an experimental study of electron spin waves in atomic hydrogen gas compressed to high densities of $\sim 5 \times 10^{18}$ cm$^{-3}$ at temperatures ranging from 0.26 to 0.6 K in strong magnetic field of 4.6 T. Hydrogen gas is in a quantu
Externí odkaz:
http://arxiv.org/abs/1609.08432
Autor:
Toikka, L. A., Suominen, K. -A.
We consider analytically the dynamics of an arbitrary number and configuration of vortices in an annular Bose-Einstein condensate obtaining expressions for the free energy and vortex precession rates to logarithmic accuracy. We also obtain lower boun
Externí odkaz:
http://arxiv.org/abs/1503.08919
Autor:
Vainio, O., Ahokas, J., Järvinen, J., Lehtonen, L., Novotny, S., Sheludiakov, S., Suominen, K. -A., Vasiliev, S., Zvezdov, D., Khmelenko, V. V., Lee, D. M.
Publikováno v:
Phys. Rev. Lett. 114, 125304 (2015)
We report on experimental observation of BEC-like behaviour of quantized electron spin waves (magnons) in a dense gas of spin polarized atomic hydrogen. The magnons are trapped and controlled with inhomogeneous magnetic fields, and described by a Sch
Externí odkaz:
http://arxiv.org/abs/1502.03963
Autor:
Toikka, L. A., Suominen, K. -A.
Publikováno v:
J. Phys. B: At. Mol. Opt. Phys. 47, 085301 (2014)
We show how boundary effects can cause a Bose-Einstein condensate to periodically oscillate between a (circular) array of quantised vortex-antivortex pairs and a (ring) dark soliton. If the boundary is restrictive enough, the ring dark soliton become
Externí odkaz:
http://arxiv.org/abs/1401.2750
Publikováno v:
J. Phys. B: At. Mol. Opt. Phys. 47, 021002 (2014)
We propose a protocol for the simultaneous controlled creation of multiple concentric ring dark solitons in a toroidally trapped Bose-Einstein condensate. The decay of these solitons into a vortex-antivortex necklace shows revivals of the soliton str
Externí odkaz:
http://arxiv.org/abs/1309.0732
Autor:
Lehto, J., Suominen, K. -A.
Level crossing models for two-state quantum systems are applicable to a wide variety of physical problems. We address the special case of level glancing, i.e., when energy levels reach a degeneracy at a specific point of time, but never actually cros
Externí odkaz:
http://arxiv.org/abs/1205.6604
Autor:
Vainio, O., Ahokas, J., Novotny, S., Sheludyakov, S., Zvezdov, D., Suominen, K. -A., Vasiliev, S.
We present a high magnetic field study of electron spin waves in atomic hydrogen gas compressed to high densities of 10^18 cm^-3 at temperatures ranging from 0.26 to 0.6 K. We observed a variety of spin wave modes caused by the identical spin rotatio
Externí odkaz:
http://arxiv.org/abs/1112.3775
We study the strong coupling limit of a quadratic-nonlinear Landau-Zener problem for coherent photo- and magneto-association of cold atoms taking into account the atom-atom, atom-molecule, and molecule-molecule elastic scattering. Using an exact thir
Externí odkaz:
http://arxiv.org/abs/0911.0456
Publikováno v:
J. Phys. B 42, 221002 (2009)
We present a rigorous analysis of the Landau-Zener linear-in-time term crossing problem for quadratic-nonlinear systems relevant to the coherent association of ultracold atoms in degenerate quantum gases. Our treatment is based on an exact third-orde
Externí odkaz:
http://arxiv.org/abs/0909.0536