Near-optimal two-mode spin squeezing via feedback

Abstract

We propose a feedback scheme for the production of two-mode spin squeezing. We determine a general expression for the optimal feedback, which is also applicable to the case of single-mode spin squeezing. The two-mode spin squeezed states obtained via this feedback are optimal for j=1/2 and are very close to optimal for j>1/2. In addition, the master equation suggests a Hamiltonian that would produce two-mode spin squeezing without feedback, and is analogous to the two-axis countertwisting Hamiltonian in the single mode case.

10 pages, 6 figures, journal version

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• Spin squeezing via quantum feedback
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Cited by in corpus (12)

• Quantum metrology with nonclassical states of atomic ensembles
• Quantum spin squeezing
• Spin squeezing and pairwise entanglement for symmetric multiqubit states
• Unconditional two-mode squeezing of separated atomic ensembles
• Continuous quantum nondemolition feedback and unconditional atomic spin squeezing
• Entanglement generation and Hamiltonian simulation in Continuous-Variable Systems
• Relations between bosonic quadrature squeezing and atomic spin squeezing
• Entanglement and spin squeezing in the three-qubit transverse Ising model
• Dynamics of entanglement between two atomic samples with spontaneous scattering
• Equivalence between two-mode spin squeezed states and pure entangled states with equal spin
• Quasideterministic generation of maximally entangled states of two mesoscopic atomic ensembles by adiabatic quantum feedback
• Spin squeezing an ultracold molecule