Thermal conductivity of anisotropic and frustrated spin-½ chains

We analyze the thermal conductivity of anisotropic and frustrated spin-1/2 chains using analytical and numerical techniques. This includes mean-field theory based on the Jordan-Wigner transformation, bosonization, and exact diagonalization of systems with N ≲ 18 sites. We present results for the tem...

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Detalles Bibliográficos
Autores: Heidrich Meisner, Fabián, Honecker, Andreas, Cabra, Daniel Carlos, Brenig, Wolfram
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2002
País:Argentina
Institución:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/126203
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/126203
Access Level:acceso abierto
Palabra clave:Física
Ciencias Exactas
thermal conductivity
Jordan-Wigner transformation
Anisotropy
Descripción
Sumario:We analyze the thermal conductivity of anisotropic and frustrated spin-1/2 chains using analytical and numerical techniques. This includes mean-field theory based on the Jordan-Wigner transformation, bosonization, and exact diagonalization of systems with N ≲ 18 sites. We present results for the temperature dependence of the zero-frequency weight of the conductivity for several values of the anisotropy Δ. In the gapless regime, we show that the mean-field theory compares well to known results and that the low-temperature limit is correctly described by bosonization. In the antiferromagnetic and ferromagnetic gapped regime, we analyze the temperature dependence of the thermal conductivity numerically. The convergence of the finite-size data is remarkably good in the ferromagnetic case. Finally, we apply our numerical method and mean-field theory to the frustrated chain where we find a good agreement of these two approaches on finite systems. Our numerical data do not yield evidence for a diverging thermal conductivity in the thermodynamic limit in case of the antiferromagnetic gapped regime of the frustrated chain.