Magnetization plateaux and jumps in frustrated four-leg spin tubes in magnetic fields

We study the ground state phase diagram of a frustrated spin-1/2 four-leg tube in an external magnetic field. We explore the parameter space of this model in the regime of all-antiferromagnetic exchange couplings by means of three different approaches: density matrix renormalization group (DMRG), a...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Rosales, Héctor Diego, Arlego, Marcelo José Fabián, Gómez Albarracín, Flavia Alejandra
Formato: Objeto de conferencia
Lenguaje:Inglés
Publicado: 2014
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/85327
Aporte de:
Descripción
Sumario:We study the ground state phase diagram of a frustrated spin-1/2 four-leg tube in an external magnetic field. We explore the parameter space of this model in the regime of all-antiferromagnetic exchange couplings by means of three different approaches: density matrix renormalization group (DMRG), a low-energy effective Hamiltonian (LEH) and a Hartree variational approach (HVA). We find that in the limit of weakly interacting plaquettes, singlet and triplet states play an important role in the formation of magnetization plateaux. We study the transition regions numerically and analytically, and find that they are described, at first order in a strong- coupling expansion, by an XXZ spin-1/2 chain in a magnetic field. These results are consistent with the DMRG and HVA calculations.