DOI: https://doi.org/10.30970/jps.02.263
DYNAMIC PROPERTIES OF SPIN-½ XY CHAINS
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Journal of Physical Studies 2(2), 263–268 (1998)
DOI: https://doi.org/10.30970/jps.02.263 DYNAMIC PROPERTIES OF SPIN-½ XY CHAINS |
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O. Derzhko\dagger,\ddagger, T. Krokhmalskii\dagger
\daggerInstitute for Condensed Matter Physics,
1 Svientsitskii Str., Lviv, UA-290011, Ukraine
\ddaggerIvan Franko Lviv State University,
Chair of Theoretical Physics,
12 Drahomanov Str., Lviv, UA-290005, Ukraine
E–mail: derzhko@icmp.lviv.ua, krokhm@icmp.lviv.ua
We have considered a numerical scheme for the calculation of the equilibrium properties of spin–$\frac{1}{2}$ $XY$ chains. Within its frames it is necessary to solve in the last resort only the $2N\times 2N$ eigenvalue and eigenvector problem but not the $2^N\times 2^N$ one as for an arbitrary system consisting of $N$ spins $\frac{1}{2}$. To illustrate the approach we have presented some new results. Namely, the $xx$ dynamic structure factor for the Ising model in transverse field, the density of states for the isotropic chain with random intersite couplings and transverse fields that linearly depend on the surrounding couplings, and the $zz$ dynamic structure factor for the Ising model in the random transverse field. The results obtained are hoped to be useful for an interpretation of observable data for one–dimensional spin–$\frac{1}{2}$ $XY$ substances.