We report the observation of half-quantum vortices (HQVs) in the easy-plane polar phase of an antiferromagnetic spinor Bose-Einstein condensate. Using in-situ magnetization-sensitive imaging, we observe that a singly charged quantum vortex dissociates into a pair of HQVs with opposite core magnetization. The dissociation dynamics is investigated by measuring the temporal evolution of the separation distance of the HQV pair. The separating behavior of the HQVs shows the short-range nature of their interactions. We observe that the dissociation process is activated faster with larger thermal spin fluctuations in the condensate, confirming the energetic instability of a singly charged vortex state.We report the observation of half-quantum vortices (HQVs) in the easy-plane polar phase of an antiferromagnetic spinor Bose-Einstein condensate. Using in-situ magnetization-sensitive imaging, we observe that a singly charged quantum vortex dissociates into a pair of HQVs with opposite core magnetization. The dissociation dynamics is investigated by measuring the temporal evolution of the separation distance of the HQV pair. The separating behavior of the HQVs shows the short-range nature of their interactions. We observe that the dissociation process is activated faster with larger thermal spin fluctuations in the condensate, confirming the energetic instability of a singly charged vortex state.

Bulletin of the American Physical SocietyMar 19, 20150 citations

Dynamics of Charged Quantized Vortices

Makoto Tsubota, Hiroyuki Adachi

arXiv:0909.2151Journal of Low Temperature PhysicsAug 3, 20092 citations

Dynamics of Quantum Vortices

Lara Thompson, Philip C. E. Stamp

Bulletin of the American Physical SocietyMar 12, 20080 citations

Half-Quantum Vortices in an Antiferromagnetic Spinor Bose-Einstein Condensate

Sang Won Seo, Seji Kang, Woo Jin Kwon +1 more

We report on the observation of half-quantum vortices (HQVs) in the easy-plane polar phase of an antiferromagnetic spinor Bose-Einstein condensate. Using in situ magnetization-sensitive imaging, we observe that pairs of HQVs with opposite core magnetization are generated when singly charged quantum vortices are injected into the condensate. The dynamics of HQV pair formation is characterized by measuring the temporal evolutions of the pair separation distance and the core magnetization, which reveals the short-range nature of the repulsive interactions between the HQVs. We find that spin fluctuations arising from thermal population of transverse magnon excitations do not significantly affect the HQV pair formation dynamics. Our results demonstrate the instability of a singly charged vortex in the antiferromagnetic spinor condensate.We report on the observation of half-quantum vortices (HQVs) in the easy-plane polar phase of an antiferromagnetic spinor Bose-Einstein condensate. Using in situ magnetization-sensitive imaging, we observe that pairs of HQVs with opposite core magnetization are generated when singly charged quantum vortices are injected into the condensate. The dynamics of HQV pair formation is characterized by measuring the temporal evolutions of the pair separation distance and the core magnetization, which reveals the short-range nature of the repulsive interactions between the HQVs. We find that spin fluctuations arising from thermal population of transverse magnon excitations do not significantly affect the HQV pair formation dynamics. Our results demonstrate the instability of a singly charged vortex in the antiferromagnetic spinor condensate.

arXiv:1503.05648Physical Review LettersJul 1, 2015113 citations

On the dynamics of quantum vortices

Richard J. Creswick, Harry L. Morrison

Physics Letters AMar 1, 198038 citations

Thermal friction on quantum vortices in a Bose-Einstein condensate

Geol Moon, Woo Jin Kwon, Hyunjik Lee +1 more

We investigate the dissipative dynamics of a corotating vortex pair in a highly oblate axisymmetric Bose-Einstein condensate trapped in a harmonic potential. The initial vortex state is prepared by creating a doubly charged vortex at the center of the condensate and letting it dissociate into two singly charged vortices. The separation of the vortex pair gradually increases over time and its increasing rate becomes higher with increasing the sample temperature $T$ . The evolution of the vortex state is well described with a dissipative point vortex model including longitudinal friction on the vortex motion. For condensates of sodium atoms having a chemical potential of $\ensuremath{\mu}\ensuremath{\approx}{k}_{B}\ifmmode\times\else\texttimes\fi{}120$ nK, we find that the dimensionless friction coefficient $\ensuremath{\alpha}$ increases from 0.01 to 0.03 over the temperature range of $200\text{nK}<T<450$ nK.We investigate the dissipative dynamics of a corotating vortex pair in a highly oblate axisymmetric Bose-Einstein condensate trapped in a harmonic potential. The initial vortex state is prepared by creating a doubly charged vortex at the center of the condensate and letting it dissociate into two singly charged vortices. The separation of the vortex pair gradually increases over time and its increasing rate becomes higher with increasing the sample temperature $T$. The evolution of the vortex state is well described with a dissipative point vortex model including longitudinal friction on the vortex motion. For condensates of sodium atoms having a chemical potential of $\ensuremath{\mu}\ensuremath{\approx}{k}_{B}\ifmmode\times\else\texttimes\fi{}120$ nK, we find that the dimensionless friction coefficient $\ensuremath{\alpha}$ increases from 0.01 to 0.03 over the temperature range of $200\text{nK}<T<450$ nK.

arXiv:1509.02236Physical Review ANov 20, 201541 citations

T

. The evolution of the vortex state is well described with a dissipative point vortex model including longitudinal friction on the vortex motion. For condensates of sodium atoms having a chemical potential of $\ensuremath{\mu}\ensuremath{\approx}{k}_{B}\ifmmode\times\else\texttimes\fi{}120$ nK, we find that the dimensionless friction coefficient $\ensuremath{\alpha}$ increases from 0.01 to 0.03 over the temperature range of

200\text{nK}<T<450

nK.