We present analytic weak-coupling and numerical finite-chain results for the specific heat, the longitudinal zero-field susceptibility, and the longitudinal dynamic form factor of the planar ferromagnetic $\mathrm{xxz}$ chain at finite temperatures. It is shown that the "bound state" probed by the dynamic form factor ${S}_{\mathrm{zz}}(q,\ensuremath{\omega})$ within the Hartree-Fock approximation has to be interpreted as the first moment of ${S}_{\mathrm{zz}}$ of the states lying above the continuum appearing in the isotropic $\mathrm{xy}$ model.We present analytic weak-coupling and numerical finite-chain results for the specific heat, the longitudinal zero-field susceptibility, and the longitudinal dynamic form factor of the planar ferromagnetic $\mathrm{xxz}$ chain at finite temperatures. It is shown that the "bound state" probed by the dynamic form factor ${S}_{\mathrm{zz}}(q,\ensuremath{\omega})$ within the Hartree-Fock approximation has to be interpreted as the first moment of ${S}_{\mathrm{zz}}$ of the states lying above the continuum appearing in the isotropic $\mathrm{xy}$ model.

Physical review. B, Condensed matterJun 1, 19834 citations

Dynamical Spin Susceptibility in the t–J Model in the Superconducting Phase

Ranjan Chaudhury

Theoretical and Mathematical PhysicsJul 1, 20033 citations

Anomalous Spin Dynamics in Doped Quantum Antiferromagnets

Janez Jaklič, Peter Prelovšek

Finite-temperature spin dynamics in the planar $t\ensuremath{-}J$ model are studied using a method based on the Lanczos diagonalization of small systems. The dynamical spin structure factor at moderate dopings shows the coexistence of free-fermion-like and spin-fluctuation time scales. At $T<J$ , low-frequency and static susceptibilities show a pronounced $T$ dependence, supporting a scenario related to the marginal Fermi liquid one, for the explanation of neutron-scattering and NMR relaxation experiments in cuprates. Calculated NMR relaxation rates reasonably reproduce experimental ones.Finite-temperature spin dynamics in the planar $t\ensuremath{-}J$ model are studied using a method based on the Lanczos diagonalization of small systems. The dynamical spin structure factor at moderate dopings shows the coexistence of free-fermion-like and spin-fluctuation time scales. At $T<J$, low-frequency and static susceptibilities show a pronounced $T$ dependence, supporting a scenario related to the marginal Fermi liquid one, for the explanation of neutron-scattering and NMR relaxation experiments in cuprates. Calculated NMR relaxation rates reasonably reproduce experimental ones.

arXiv:cond-mat/9410085Physical Review LettersApr 24, 199542 citations

Universality of Charge and Spin Response in Doped Antiferromagnets

Peter Prelovšek, Janez Jaklič

Recent results for the finite-temperature static and dynamical properties of the planar $t-J$ model, obtained by a novel numerical method for small correlated systems, are reviewed. Of particular interest are $T>0$ charge and spin response functions: optical conductivity $σ(ω)$ and spin susceptibility $χ(\vec q,ω)$ , which show very universal features at intermediate doping. In spin dynamics the universality is best seen in the local spin correlation function, which appears to be $T$ -independent and only weakly doping dependent. Results apply directly to the inelastic neutron scattering and to the NMR relaxation experiments in cuprates. Analysing $σ(ω)$ we find that the current correlation function $C(ω)$ is nearly $T$ - and moreover $ω$ -independent in the regime $TRecent results for the finite-temperature static and dynamical properties of the planar $t-J$ model, obtained by a novel numerical method for small correlated systems, are reviewed. Of particular interest are $T>0$ charge and spin response functions: optical conductivity $σ(ω)$ and spin susceptibility $χ(\vec q,ω)$, which show very universal features at intermediate doping. In spin dynamics the universality is best seen in the local spin correlation function, which appears to be $T$-independent and only weakly doping dependent. Results apply directly to the inelastic neutron scattering and to the NMR relaxation experiments in cuprates. Analysing $σ(ω)$ we find that the current correlation function $C(ω)$ is nearly $T$- and moreover $ω$-independent in the regime $T

arXiv:cond-mat/9601073Jan 18, 19960 citations

\mathrm{xxz}

chain at finite temperatures. It is shown that the "bound state" probed by the dynamic form factor ${S}_{\mathrm{zz}}(q,\ensuremath{\omega})$ within the Hartree-Fock approximation has to be interpreted as the first moment of

{S}_{\mathrm{zz}}

of the states lying above the continuum appearing in the isotropic

\mathrm{xy}

model.

T<J

, low-frequency and static susceptibilities show a pronounced

T

dependence, supporting a scenario related to the marginal Fermi liquid one, for the explanation of neutron-scattering and NMR relaxation experiments in cuprates. Calculated NMR relaxation rates reasonably reproduce experimental ones.

Recent results for the finite-temperature static and dynamical properties of the planar

t-J

model, obtained by a novel numerical method for small correlated systems, are reviewed. Of particular interest are

T>0

charge and spin response functions: optical conductivity

σ(ω)

and spin susceptibility

χ(\vec q,ω)

, which show very universal features at intermediate doping. In spin dynamics the universality is best seen in the local spin correlation function, which appears to be

T

-independent and only weakly doping dependent. Results apply directly to the inelastic neutron scattering and to the NMR relaxation experiments in cuprates. Analysing

σ(ω)

we find that the current correlation function

C(ω)

is nearly

T

- and moreover

ω

-independent in the regime $T