Spin-squeezing property of weighted graph states
نویسندگان
چکیده
منابع مشابه
Spin squeezing in nonlinear spin-coherent states
We introduce the nonlinear spin-coherent state (SCS) via its ladder operator formalism and propose a type of nonlinear SCS by the nonlinear time evolution of the SCS. By a new version of spectroscopic squeezing criteria we study the spin squeezing in both the SCS and the nonlinear SCS. The results show that the SCS is not squeezed in the x, y and z directions, and the nonlinear SCS may be squee...
متن کاملSpin squeezing inequalities and entanglement of N qubit states.
We derive spin squeezing inequalities that generalize the concept of the spin squeezing parameter and provide necessary and sufficient conditions for genuine 2-, or 3-qubit entanglement for symmetric states, and sufficient condition for N-qubit states. Our inequalities have a clear physical interpretation as entanglement witnesses, can be easily measured, and are given by complex but elementary...
متن کاملMean spin direction and spin squeezing in superpositions of spin coherent states
We consider the mean spin direction (MSD) of superpositions of two spin coherent states (SCS) | ± μ〉, and superpositions of |μ〉 and |μ∗〉 with a relative phase. We find that the azimuthal angle exhibits a π transition for both states when we vary the relative phase. The spin squeezing of the states, and the bosonic counterpart of the mean spin direction are also discussed. c © Versita Warsaw and...
متن کاملSpin squeezing and pairwise entanglement for symmetric multiqubit states
We show that spin squeezing implies pairwise entanglement for arbitrary symmetric multiqubit states. If the squeezing parameter is less than or equal to 1, we demonstrate a quantitative relation between the squeezing parameter and the concurrence for the even and odd states. We prove that the even states generated from the initial state with all qubits being spin down, via the one-axis twisting...
متن کاملVacuum spin squeezing
We investigate the generation of entanglement (spin squeezing) in an optical-transition atomic clock through the coupling to an optical cavity in its vacuum state. We show that if each atom is prepared in a superposition of the ground state and a long-lived electronic excited state, and viewed as a spin-1/2 system, then the collective vacuum light shift entangles the atoms, resulting in a squee...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review A
سال: 2012
ISSN: 1050-2947,1094-1622
DOI: 10.1103/physreva.86.023812