Magnetization plateaux and jumps in a frustrated four-leg spin tube under a magnetic field

Abstract

We study the ground state phase diagram of a frustrated spin-1/2 four-leg spin 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: analysis of low-energy effective Hamiltonian (LEH), a Hartree variational approach (HVA) and density matrix renormalization group (DMRG) for finite clusters. We find that in the limit of weakly interacting plaquettes, low-energy singlet, triplet and quintuplet states play an important role in the formation of fractional 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; the second-order terms give corrections to the XXZ model. All techniques provide consistent results which allow us to predict the existence of fractional plateaux in an important region in the space of parameters of the model.

10 pages, 7 figures. Accepted for publication in Physical Review B

References in corpus (5)

• The ALPS project release 1.3: open source software for strongly correlated systems
• Magnetic characterization of the frustrated three-leg ladder compound [(CuCl2tachH)3Cl]Cl2
• Condensation of magnons and spinons in a frustrated ladder
• Heat capacity uncovers physics of a frustrated spin tube
• Ising phases of Heisenberg ladders in a magnetic field

Cited by in corpus (3)

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• Low-energy spin excitations in field-induced phases of the spin-ladder antiferromagnet BiCu${}_2$PO${}_6$