Quantum phase transitions and continuous observation of spinor dynamics in an antiferromagnetic condensate.
Condensates of spin-1 sodium display rich spin dynamics due to the antiferromagnetic nature of the interactions in this system. We use Faraday rotation spectroscopy to make a continuous and minimally destructive measurement of the dynamics over multiple spin oscillations on a single evolving condensate. This method provides a sharp signature to locate a magnetically tuned separatrix in phase space which depends on the net magnetization. We also observe a phase transition from a two- to a three-component condensate at a low but finite temperature using a Stern-Gerlach imaging technique. This transition should be preserved as a zero-temperature quantum phase transition.
Liu
Y
Y
National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Jung
S
S
Maxwell
S E
SE
Turner
L D
LD
Tiesinga
E
E
Lett
P D
PD