Spin- 12 XX chain in a transverse field with regularly alternating g factors: Static and dynamic properties
| Autor: | Taras Krokhmalskii, Vadim Ohanyan, Taras Verkholyak, Oleg Derzhko, Ostap Baran |
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| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Physical Review B. 102 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.102.144403 |
| Popis: | We consider the spin-$\frac{1}{2}$ isotropic XY chain in an external magnetic field directed along the $z$ axis with periodically varying $g$ factors. To reveal the effects of regularly alternating $g$ factors, we calculate various static and dynamic equilibrium quantities in the ground state and at finite temperatures. We demonstrate that because of the regularly alternating $g$ factors the saturation field may disappear and the field dependence of the susceptibility in the ground state has additional logarithmic singularity at zero field. Moreover, the zero-field susceptibility has a logarithmic singularity as $T\ensuremath{\rightarrow}0$. Furthermore, the dynamic structure factors exhibit much more structure in the ``wave vector--frequency'' plane that can be traced out to modifications of the two-fermion excitation continua which exclusively determine ${S}_{zz}(\ensuremath{\kappa},\ensuremath{\omega})$ and dominate the properties of ${S}_{xx}(\ensuremath{\kappa},\ensuremath{\omega})$. We discuss what changes can be observed in dynamic experiments on the corresponding substances. |
| Databáze: | OpenAIRE |
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