Dynamical instabilities in a $^{87}\text{R}\text{b}$ $F=1$ spinor Bose-Einstein condensate are used as a parametric amplifier of quantum spin fluctuations. We demonstrate the spectrum of this amplifier to be tunable, in quantitative agreement with theory. We quantify the microscopic spin fluctuations of the initially paramagnetic condensate by applying this amplifier and measuring the resulting macroscopic magnetization. The variance of these fluctuations agrees with predictions of a beyond-mean-field theory. This spin amplifier is thus shown to be nearly quantum limited at a gain as high as 30 dB.Dynamical instabilities in a $^{87}\text{R}\text{b}$ $F=1$ spinor Bose-Einstein condensate are used as a parametric amplifier of quantum spin fluctuations. We demonstrate the spectrum of this amplifier to be tunable, in quantitative agreement with theory. We quantify the microscopic spin fluctuations of the initially paramagnetic condensate by applying this amplifier and measuring the resulting macroscopic magnetization. The variance of these fluctuations agrees with predictions of a beyond-mean-field theory. This spin amplifier is thus shown to be nearly quantum limited at a gain as high as 30 dB.

arXiv:0806.1553Physical Review AApr 28, 2009125 citations

Formation of Magnetic Structure in a Spinor Bose Einstein Condensate

A. N. Wenz, Jennie Guzman, Kater W. Murch +1 more

Bulletin of the American Physical SocietyMay 27, 20100 citations

Exact Eigenstates and Magnetic Response of Spin-1 and Spin-2 Bose-Einstein Condensates

Masato Koashi, Masahito Ueda

The exact eigenspectra and eigenstates of spin-1 and spin-2 Bose-Einstein condensates (BECs) are found, and their response to a weak magnetic field is studied and compared with their mean-field counterparts. Whereas mean-field theory predicts the vanishing population of the zero magnetic-quantum-number component of a spin-1 antiferromagnetic BEC, the component is found to become populated as the magnetic field decreases. The spin-2 BEC exhibits an even richer magnetic response due to quantum correlations among three bosons.The exact eigenspectra and eigenstates of spin-1 and spin-2 Bose-Einstein condensates (BECs) are found, and their response to a weak magnetic field is studied and compared with their mean-field counterparts. Whereas mean-field theory predicts the vanishing population of the zero magnetic-quantum-number component of a spin-1 antiferromagnetic BEC, the component is found to become populated as the magnetic field decreases. The spin-2 BEC exhibits an even richer magnetic response due to quantum correlations among three bosons.

arXiv:cond-mat/9906313Physical Review LettersFeb 7, 2000269 citations

Bose-Einstein condensation in magnetic systems under strong fields

Daniel Reyes, M. A. Contínentino, Armando Paduan-Filho

Jan 17, 20080 citations

Symmetry-breaking magnetization dynamics of spinor dipolar Bose-Einstein condensates

Shoichi Hoshi, Hiroki Saito

The symmetry-breaking magnetization dynamics of a spin-1 Bose-Einstein condensate (BEC) due to the dipole-dipole interaction are investigated using the mean-field and Bogoliubov theories. When a magnetic field is applied along the symmetry axis of a pancake-shaped BEC in the $m=0$ hyperfine sublevel, transverse magnetization develops breaking the chiral or axial symmetry. A variety of magnetization patterns are formed depending on the strength of the applied magnetic field. The proposed phenomena can be observed in $^{87}\mathrm{Rb}$ and $^{23}\mathrm{Na}$ condensates.The symmetry-breaking magnetization dynamics of a spin-1 Bose-Einstein condensate (BEC) due to the dipole-dipole interaction are investigated using the mean-field and Bogoliubov theories. When a magnetic field is applied along the symmetry axis of a pancake-shaped BEC in the $m=0$ hyperfine sublevel, transverse magnetization develops breaking the chiral or axial symmetry. A variety of magnetization patterns are formed depending on the strength of the applied magnetic field. The proposed phenomena can be observed in $^{87}\mathrm{Rb}$ and $^{23}\mathrm{Na}$ condensates.

arXiv:0911.2741Physical Review AJan 27, 201012 citations

Bose-Einstein condensation in magnetic traps. Introduction to the theory

Лев П. Питаевский

Uspekhi Fizicheskih NaukJun 1, 199888 citations

Dynamical instabilities in a

^{87}\text{R}\text{b}

F=1

spinor Bose-Einstein condensate are used as a parametric amplifier of quantum spin fluctuations. We demonstrate the spectrum of this amplifier to be tunable, in quantitative agreement with theory. We quantify the microscopic spin fluctuations of the initially paramagnetic condensate by applying this amplifier and measuring the resulting macroscopic magnetization. The variance of these fluctuations agrees with predictions of a beyond-mean-field theory. This spin amplifier is thus shown to be nearly quantum limited at a gain as high as 30 dB.

m=0

hyperfine sublevel, transverse magnetization develops breaking the chiral or axial symmetry. A variety of magnetization patterns are formed depending on the strength of the applied magnetic field. The proposed phenomena can be observed in

^{87}\mathrm{Rb}

and

^{23}\mathrm{Na}

condensates.