Quantum spin dynamics of the axial antiferromagnetic spin- $\frac{1}{2}$ XXZ chain in a longitudinal magnetic fieldQuantum spin dynamics of the axial antiferromagnetic spin-$\frac{1}{2}$ XXZ chain in a longitudinal magnetic field

Wang Yang, Jianda Wu, Shenglong Xu +2 more

Feb 7, 20173 citations

Dynamical properties of phonons in the XY spin chain coupled with lattices

Fei Ye, Guo-Hui Ding, Bo-Wei Xu

We study the dynamical properties of the phonons in the $\mathrm{XY}$ spin chain coupled with lattices subjected to the applied magnetic field with the path-integral approach. Dynamical structure factor is calculated in the presence of the magnetic field. A critical value of the bare \ensuremath{\pi}-mode phonon frequency ${\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ is given such that for ${\ensuremath{\Omega}}_{\ensuremath{\pi}}<{\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ the spin-Peierls transition is in the soft-mode regime and for ${\ensuremath{\Omega}}_{\ensuremath{\pi}}>{\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ it is in the central-peak regime. We find that ${\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ depends on the magnitude of the applied magnetic field.We study the dynamical properties of the phonons in the $\mathrm{XY}$ spin chain coupled with lattices subjected to the applied magnetic field with the path-integral approach. Dynamical structure factor is calculated in the presence of the magnetic field. A critical value of the bare \ensuremath{\pi}-mode phonon frequency ${\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ is given such that for ${\ensuremath{\Omega}}_{\ensuremath{\pi}}<{\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ the spin-Peierls transition is in the soft-mode regime and for ${\ensuremath{\Omega}}_{\ensuremath{\pi}}>{\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ it is in the central-peak regime. We find that ${\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ depends on the magnitude of the applied magnetic field.

Physical review. B, Condensed matterAug 14, 20012 citations

Dynamics of alternating spin chains

Joachim Stolze, Oleg Derzhko, Taras Krokhmalskii

Czechoslovak Journal of PhysicsFeb 1, 20020 citations

Low-energy dynamics of a magnetic impurity in a quantum spin chain: Role of local levels

Andrei A. Zvyagin

The characteristics of the nuclear magnetic resonance (NMR), the contributions to the spin-lattice relaxation rate, and Knight shift of the resonance position are calculated exactly for a model spin- $1/2$ $XY$ chain with the magnetic impurity. It is shown that the deviations of the impurity's coupling to the chain and the effective impurity's $g$ factor from the values in the host spin chain yield special features in the temperature and magnetic field behavior for these NMR characteristics. The role of impurity-induced local levels in the NMR low-energy spin dynamics of spin chains is determined.The characteristics of the nuclear magnetic resonance (NMR), the contributions to the spin-lattice relaxation rate, and Knight shift of the resonance position are calculated exactly for a model spin-$1/2$ $XY$ chain with the magnetic impurity. It is shown that the deviations of the impurity's coupling to the chain and the effective impurity's $g$ factor from the values in the host spin chain yield special features in the temperature and magnetic field behavior for these NMR characteristics. The role of impurity-induced local levels in the NMR low-energy spin dynamics of spin chains is determined.

Physical Review BApr 20, 20125 citations

Quantum spin dynamics of the axial antiferromagnetic spin-

\frac{1}{2}

XXZ chain in a longitudinal magnetic field

We study the dynamical properties of the phonons in the

\mathrm{XY}

spin chain coupled with lattices subjected to the applied magnetic field with the path-integral approach. Dynamical structure factor is calculated in the presence of the magnetic field. A critical value of the bare \ensuremath{\pi}-mode phonon frequency ${\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ is given such that for ${\ensuremath{\Omega}}_{\ensuremath{\pi}}<{\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ the spin-Peierls transition is in the soft-mode regime and for ${\ensuremath{\Omega}}_{\ensuremath{\pi}}>{\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ it is in the central-peak regime. We find that ${\ensuremath{\Omega}}_{\ensuremath{\pi},c}$ depends on the magnitude of the applied magnetic field.

The characteristics of the nuclear magnetic resonance (NMR), the contributions to the spin-lattice relaxation rate, and Knight shift of the resonance position are calculated exactly for a model spin-

1/2

XY

chain with the magnetic impurity. It is shown that the deviations of the impurity's coupling to the chain and the effective impurity's

g

factor from the values in the host spin chain yield special features in the temperature and magnetic field behavior for these NMR characteristics. The role of impurity-induced local levels in the NMR low-energy spin dynamics of spin chains is determined.