Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Spin squeezing of superposition of biaxial State and two qubit bell state

Ashourisheikhi, S.

Published Jan 1, 2014• 0 citations
OpenAlex

Abstract

In this study we investigate the spin squeezing in superposition of a Biaxial state (Mallesh et al. in J. Phys. A, Math. Gen. 33:779-789, 2000 and Sirsi in Theoretical studies on spin distributions in external electric and magnetic fields, 1995) and Bell state. Numerical and analytical solutions for the length of mean spin, mean spin direction and spin squeezing are given. It is shown that both the mean spin direction and spin squeezing parameter are determined by the coefficients of superposition and the relative phase. © 2013 Springer Science+Business Media New York.

Related papers

Squeezing of a coupled state of two spin-1 systems

K. S. Akhilesh

The nature of spin squeezing has been studied earlier for a coupled state of two spinors by Usha Devi et. al. (J. Phys. A: Math. Gen. 36 5333 (2003)). In this paper, we extend this study to a coupled state of two spin-1 systems. Here, we show that the direct product of two spin-1 states exhibits squeezing unlike the direct product of two spinors. We investigate the nature of squeezing for non-separable coupled state of two spin-1 systems and identify the parameters which are responsible for the existence of squeezing. We also provide ways to generate them by external interactions.

arXiv:2207.13439•Jul 27, 2022•0 citations

Mean spin direction and spin squeezing in superpositions of spin coherent states

Dong Yan, Xiaoguang Wang, Lijun Song +1 more

Abstract 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.

Open Physics•Jan 1, 2007•41 citations

Spin Squeezing of Superposition of Biaxial State and Two Qubit Bell State

Sakineh Ashourisheikhi

arXiv:1308.5298•International Journal of Theoretical Physics•Nov 14, 2013•0 citations

Spin squeezing and entanglement in superposition of nonlinear spin coherent states

Azita Naji, Mojtaba Jafarpour, Fatemeh Sammak

We study squeezing and entanglement in superposition of a class of nonlinear spin coherent states. We analyze these properties as a function of the coherence and superposition parameters, number of qubits and the Hamiltonians involved, by presenting analytical and numerical results. We specifically observe that a subclass of these states, the even non-linear cat states are maximally entangled and squeezed, while another related subclass, the odd non-linear cat states, are entangled but not squeezed at all.

Journal of Physics Communications•Apr 12, 2018•1 citation

Spin squeezing in dipolar spinor condensates

Dariusz Kajtoch, Emilia Witkowska

We study the effect of dipolar interactions on the level of squeezing in spin-1 Bose-Einstein condensates by using the single mode approximation. We limit our consideration to the SU(2) Lie subalgebra spanned by spin operators. The biaxial nature of dipolar interactions allows for dynamical generation of spin-squeezed states in the system. We analyze the phase portraits in the reduced mean-field space in order to determine positions of unstable fixed points. We calculate numerically the spin squeezing parameter showing that it is possible to reach the strongest squeezing set by the two-axis countertwisting model. We partially explain scaling with the system size by using the Gaussian approach and the frozen spin approximation.

arXiv:1512.01965•Physical Review A•Feb 17, 2016•21 citations

Spin squeezing and pairwise entanglement for symmetric multiqubit states

Xiaoguang Wang, Barry C. Sanders

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 Hamiltonian, are spin squeezed if and only if they are pairwise entangled. For the states generated via the one-axis twisting Hamiltonian with an external transverse field for any number of qubits greater than 1 or via the two-axis countertwisting Hamiltonian for any even number of qubits, the numerical results suggest that such states are spin squeezed if and only if they are pairwise entangled.

arXiv:quant-ph/0302014•Physical Review A•Jul 2, 2003•228 citations
In this study we investigate the spin squeezing in superposition of a Biaxial state (Mallesh et al. in J. Phys. A, Math. Gen. 33:779-789, 2000 and Sirsi in Theoretical studies on spin distributions in external electric and magnetic fields, 1995) and Bell state. Numerical and analytical solutions for the length of mean spin, mean spin direction and spin squeezing are given. It is shown that both the mean spin direction and spin squeezing parameter are determined by the coefficients of superposition and the relative phase. © 2013 Springer Science+Business Media New York.
The nature of spin squeezing has been studied earlier for a coupled state of two spinors by Usha Devi et. al. (J. Phys. A: Math. Gen. 36 5333 (2003)). In this paper, we extend this study to a coupled state of two spin-1 systems. Here, we show that the direct product of two spin-1 states exhibits squeezing unlike the direct product of two spinors. We investigate the nature of squeezing for non-separable coupled state of two spin-1 systems and identify the parameters which are responsible for the existence of squeezing. We also provide ways to generate them by external interactions.
We study squeezing and entanglement in superposition of a class of nonlinear spin coherent states. We analyze these properties as a function of the coherence and superposition parameters, number of qubits and the Hamiltonians involved, by presenting analytical and numerical results. We specifically observe that a subclass of these states, the even non-linear cat states are maximally entangled and squeezed, while another related subclass, the odd non-linear cat states, are entangled but not squeezed at all.
We study the effect of dipolar interactions on the level of squeezing in spin-1 Bose-Einstein condensates by using the single mode approximation. We limit our consideration to the SU(2) Lie subalgebra spanned by spin operators. The biaxial nature of dipolar interactions allows for dynamical generation of spin-squeezed states in the system. We analyze the phase portraits in the reduced mean-field space in order to determine positions of unstable fixed points. We calculate numerically the spin squeezing parameter showing that it is possible to reach the strongest squeezing set by the two-axis countertwisting model. We partially explain scaling with the system size by using the Gaussian approach and the frozen spin approximation.
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 Hamiltonian, are spin squeezed if and only if they are pairwise entangled. For the states generated via the one-axis twisting Hamiltonian with an external transverse field for any number of qubits greater than 1 or via the two-axis countertwisting Hamiltonian for any even number of qubits, the numerical results suggest that such states are spin squeezed if and only if they are pairwise entangled.