A bond operator representation of quantum $S=1$ spins is developed along the same line to the bond operator representation of quantum $S=\frac{1}{2}$ spins. The two representations are then applied to investigate the magnetization of the isotropic spin- $1$ antiferromagnetic chains and the spin- $\frac{1}{2}$ and spin- $1$ spin ladders. With the appropriate quantum states projected out, the spin- $1$ chains and the spin- $\frac{1}{2}$ and spin- $1$ spin ladders can be mapped to effective Hamiltonians of the $\mathcal{S}=\frac{1}{2}$ pseudospins in the effective external magnetic fields. The magnetization features of the spin- $1$ chains and the spin- $\frac{1}{2}$ and spin- $1$ spin ladders are then analyzed with the use of the existing rigorous results of the spin- $\frac{1}{2}$ $\mathrm{XXZ}$ spin chains. For spin- $1$ chains, the dependences of the magnetization on the applied magnetic fields are obtained. The $m=\frac{1}{4}$ plateau appearing in the magnetization of the spin- $\frac{1}{2}$ spin ladders and the $m=\frac{1}{4},$ $\frac{1}{2},$ and $\frac{3}{4}$ plateaus in the magnetization of the spin- $1$ spin ladders are studied. The effects of the single-ion anisotropy and the related experiments on spin- $1$ spin ladders are discussed also.A bond operator representation of quantum $S=1$ spins is developed along the same line to the bond operator representation of quantum $S=\frac{1}{2}$ spins. The two representations are then applied to investigate the magnetization of the isotropic spin-$1$ antiferromagnetic chains and the spin-$\frac{1}{2}$ and spin-$1$ spin ladders. With the appropriate quantum states projected out, the spin-$1$ chains and the spin-$\frac{1}{2}$ and spin-$1$ spin ladders can be mapped to effective Hamiltonians of the $\mathcal{S}=\frac{1}{2}$ pseudospins in the effective external magnetic fields. The magnetization features of the spin-$1$ chains and the spin-$\frac{1}{2}$ and spin-$1$ spin ladders are then analyzed with the use of the existing rigorous results of the spin-$\frac{1}{2}$ $\mathrm{XXZ}$ spin chains. For spin-$1$ chains, the dependences of the magnetization on the applied magnetic fields are obtained. The $m=\frac{1}{4}$ plateau appearing in the magnetization of the spin-$\frac{1}{2}$ spin ladders and the $m=\frac{1}{4},$ $\frac{1}{2},$ and $\frac{3}{4}$ plateaus in the magnetization of the spin-$1$ spin ladders are studied. The effects of the single-ion anisotropy and the related experiments on spin-$1$ spin ladders are discussed also.

Physical review. B, Condensed matterFeb 1, 200025 citations

Spin—Boson Systems

Luigi Accardi, Igor Vasil'evich Volovich, Yun Gang Lu

Springer eBooksJan 1, 20020 citations

Quantum Entanglement in a Spin-Orbit Coupled Bose–Einstein Condensate*

Yixiao Huang, Ning-Ju Hui, Wanfang Liu +2 more

Abstract We study the spin-field and the spin-spin entanglement in the ground state of a spin-orbit coupled Bose–Einstein condensate. It is found that the spin-field and the spin-spin entanglement can be induced by the spin-orbit coupling. By mapping the system to the Dicke-like model, the system exhibits a quantum phase transition from a normal (spin balanced) phase to superradiant (spin polarized) phase. The Dicke-like phase transition can be captured by the spin-field and the spin-spin entanglement arising from the spin-orbit coupling. The spin-field and the spin-spin entanglement increase as the Raman coupling increases in the superradiant phase, while they decrease with the Raman coupling increasing in the normal phase. We also consider the effect of a finite detuning on these entanglement show that the presence of the detuning suppresses the spin-field and the spin-spin entanglement.Abstract We study the spin-field and the spin-spin entanglement in the ground state of a spin-orbit coupled Bose–Einstein condensate. It is found that the spin-field and the spin-spin entanglement can be induced by the spin-orbit coupling. By mapping the system to the Dicke-like model, the system exhibits a quantum phase transition from a normal (spin balanced) phase to superradiant (spin polarized) phase. The Dicke-like phase transition can be captured by the spin-field and the spin-spin entanglement arising from the spin-orbit coupling. The spin-field and the spin-spin entanglement increase as the Raman coupling increases in the superradiant phase, while they decrease with the Raman coupling increasing in the normal phase. We also consider the effect of a finite detuning on these entanglement show that the presence of the detuning suppresses the spin-field and the spin-spin entanglement.

Communications in Theoretical PhysicsDec 1, 20152 citations

The Interacting Boson Model

Abraham Klein

ScienceApr 2, 19821 citation

A bond operator representation of quantum

S=1

spins is developed along the same line to the bond operator representation of quantum

S=\frac{1}{2}

spins. The two representations are then applied to investigate the magnetization of the isotropic spin-

1

antiferromagnetic chains and the spin-

\frac{1}{2}

and spin-

1

spin ladders. With the appropriate quantum states projected out, the spin-

1

chains and the spin-

\frac{1}{2}

and spin-

1

spin ladders can be mapped to effective Hamiltonians of the

\mathcal{S}=\frac{1}{2}

pseudospins in the effective external magnetic fields. The magnetization features of the spin-

1

chains and the spin-

\frac{1}{2}

and spin-

1

spin ladders are then analyzed with the use of the existing rigorous results of the spin-

\frac{1}{2}

\mathrm{XXZ}

spin chains. For spin-

1

chains, the dependences of the magnetization on the applied magnetic fields are obtained. The

m=\frac{1}{4}

plateau appearing in the magnetization of the spin-

\frac{1}{2}

spin ladders and the

m=\frac{1}{4},

\frac{1}{2},

and

\frac{3}{4}

plateaus in the magnetization of the spin-

1

spin ladders are studied. The effects of the single-ion anisotropy and the related experiments on spin-

1

spin ladders are discussed also.