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Spin squeezing in finite temperature Bose-Einstein condensates: Scaling with the system size

Alice Sinatra, Emilia Witkowska, Yvan Castin

arXiv:1112.3795The European Physical Journal Special TopicsApr 1, 201212 citations

Spin Squeezing and Non-linear Atom Interferometry with Bose-Einstein Condensates

Christan Groß

Springer thesesJan 1, 201210 citations

Spin squeezing in Bose—Einstein condensates: Limits imposed by decoherence and non-zero temperature

Alice Sinatra, Jean-Christophe Dornstetter, Yvan Castin

We consider dynamically generated spin squeezing in interacting bimodal condensates. We show that particle losses and non-zero temperature effects in a multimode theory completely change the scaling of the best squeezing for large atom numbers. We present the new scalings and we give approximate analytical expressions for the squeezing in the thermodynamic limit. Besides reviewing our recent theoretical results, we give here a simple physical picture of how decoherence acts to limit the squeezing. We show in particular that under certain conditions the decoherence due to losses and non-zero temperature acts as a simple dephasing.We consider dynamically generated spin squeezing in interacting bimodal condensates. We show that particle losses and non-zero temperature effects in a multimode theory completely change the scaling of the best squeezing for large atom numbers. We present the new scalings and we give approximate analytical expressions for the squeezing in the thermodynamic limit. Besides reviewing our recent theoretical results, we give here a simple physical picture of how decoherence acts to limit the squeezing. We show in particular that under certain conditions the decoherence due to losses and non-zero temperature acts as a simple dephasing.

arXiv:1109.2401Frontiers of PhysicsDec 12, 201142 citations

Spin squeezing in spin-1 Bose condensates

Chris Hamley, Corey Gerving, Thai M. Hoang +1 more

Bulletin of the American Physical SocietyJun 15, 20110 citations

Limit of Spin Squeezing in Finite-Temperature Bose-Einstein Condensates

Alice Sinatra, Emilia Witkowska, Jean-Christophe Dornstetter +2 more

We show that, at finite temperature, the maximum spin squeezing achievable using interactions in Bose-Einstein condensates has a finite limit when the atom number N→∞ at fixed density and interaction strength. We calculate the limit of the squeezing parameter for a spatially homogeneous system and show that it is bounded from above by the initial noncondensed fraction.

arXiv:1104.1871Physical Review LettersAug 3, 201139 citations

Limitations of squeezing due to collisional decoherence in Bose-Einstein condensates

Thomas Gasenzer

We study the limitations for entanglement due to collisional decoherence in a Bose-Einstein condensate. Specifically we consider relative number squeezing between photons and atoms coupled out from a homogeneous condensate. We study the decay of excited quasiparticle modes due to collisions in condensates of atoms with one or two internal degrees of freedom. The time evolution of these modes is determined in the linear response approximation to the deviation from equilibrium. We use Heisenberg-Langevin equations to derive equations of motion for the densities and higher correlation functions which determine the squeezing. In this way we can show that decoherence due to quasiparticle interactions imposes an important limit on the degree of number squeezing which may be achieved. Our results are also relevant for the determination of decoherence times in other experiments based on entanglement, e.g. the slowing and stopping of light in condensed atomic gases using dark states.We study the limitations for entanglement due to collisional decoherence in a Bose-Einstein condensate. Specifically we consider relative number squeezing between photons and atoms coupled out from a homogeneous condensate. We study the decay of excited quasiparticle modes due to collisions in condensates of atoms with one or two internal degrees of freedom. The time evolution of these modes is determined in the linear response approximation to the deviation from equilibrium. We use Heisenberg-Langevin equations to derive equations of motion for the densities and higher correlation functions which determine the squeezing. In this way we can show that decoherence due to quasiparticle interactions imposes an important limit on the degree of number squeezing which may be achieved. Our results are also relevant for the determination of decoherence times in other experiments based on entanglement, e.g. the slowing and stopping of light in condensed atomic gases using dark states.

arXiv:quant-ph/0202012Journal of Physics B Atomic Molecular and Optical PhysicsMay 9, 20029 citations

Spin squeezing in Bose-Einstein condensates： Limits imposed by decoherence and non-zero temperature

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Spin squeezing in Bose-Einstein condensates： Limits imposed by decoherence and non-zero temperature

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