Eur. Phys. J. D 49, 111-116 (2008)
https://doi.org/10.1140/epjd/e2008-00129-8

Collective spin tunneling in spinor Bose-Einstein condensates

¹ Department of Physics, Ritsumeikan University-BKC, Noji-Hill, Kusatsu City, 525-8577, Japan
² Laboratoire de Physique des Solides, Bâtiment 510, CNRS UMR8502 / Université Paris-Sud, Centre d'Orsay, 91405 Orsay, France

Corresponding author: ^a botet@lps.u-psud.fr

Received: 14 April 2008
Revised: 20 May 2008
Published online: 2 July 2008

Abstract

We investigate a novel aspect of rotational tunneling of the macroscopic spin for multicomponent spinor Bose-Einstein condensate (BEC). The Lagrangian is deduced from the multi-component BEC system formalism, and is written in terms of spin coherent states. From the effective Hamiltonian for the collective spin, the tunneling rate is obtained through a functional integral of the spin variable. It is pointed out that the cooperative effect between the Zeeman energy and the anisotropic nature of the spin-dependent inter-atomic interaction plays a key role for occurrence of collective spin tunneling.