[7p-A410-1~9] 4.9 Quantum Optics

▲ [7p-A410-7] Observation of self-organized coherence in dissipative spinor Bose-Einstein condensates

〇Yujiro Eto¹, Hitoshi Shibayama², Aki Torii², Hiroki Saito³, Takuya Hirano² (1.AIST, 2.Gakushuin Univ., 3.Univ. Electro.-Comm.)

Keywords:Bose-Einstein condensate, Spinor dynamics, Dissipation

Dissipation is a ubiquitous phenomenon, and it is important to understand its role in non-equilibrium dynamics. In the quantum systems, dissipation often reduce the coherence of the quantum states. But sometimes, it induces completely different effects than the decoherence. For example, strong dissipation can be used to suppress the loss and control the quantum state and quantum phase transition. Here, we have observed novel spinor dynamics caused by strong dissipation in quantum atomic gas. We have observed spontaneous magnetization with self-organized coherence in spin-2 Bose-Einstein condensates (BECs). It should be noted that spin-2 BEC of 87Rb favors the non-ferromagnetic nature due to spin-dependent elastic collision, and they are dissipative system due to large hyperfine exchange loss. These properties seemingly contradict the spontaneous magnetization and formation of coherence. We have found that these nontrivial effects are mainly due to the hyperfine changing inelastic loss, which wants to leave the ferromagnetic spins.