Quantum criticality in an asymmetric three-leg spin tube: A strong rung-coupling perspective
arXiv:1311.3041 · doi:10.1103/PhysRevB.89.054425
Abstract
We study quantum phase transitions in the asymmetric variation of the three-leg Heisenberg tube for half-odd-integer spin, with a modulation of one of the rung exchange couplings while the other two are kept constant . We focus on the strong rung-coupling regime , where is the leg coupling, and analyze the effective spin-orbital model with a transverse crystal field in detail. Applying the Abelian bosonization to the effective model, we find that the system is in the dimer phase for the general half-odd-integer-spin cases without the rung modulation; the phase transition between the dimer and Tomonaga-Luttinger-liquid phases induced by the rung modulation is of the SU(2)-symmetric Berezinskii-Kosterlitz-Thouless type. Moreover, we perform a level spectroscopy analysis for the effective model for spin-1/2 using exact diagonalization, to determine the precise transition point in the strong rung-coupling limit. The presence of the dimer phase in a small but finite region is also confirmed by a density-matrix renormalization group calculation on the original spin-tube model.
14 pages, 6 figures
References in corpus (9)
- Magnetic characterization of the frustrated three-leg ladder compound [(CuCl2tachH)3Cl]Cl2
- Frustrated three-leg spin tubes: from spin 1/2 with chirality to spin 3/2
- Quantum phase transitions of the asymmetric three-leg spin tube
- Low-lying excitations of the three-leg spin tube using the density-matrix renormalization group method
- Coefficients of bosonized dimer operators in spin-1/2 XXZ chains and their applications
- Quantum spin nanotubes -- frustration, competing orders and criticalities
- Identifying Symmetry-Protected Topological Order by Entanglement Entropy
- Quantum phase transitions in three-leg spin tubes
- Quantitative expression of the spin gap via bosonization for a dimerized spin-1/2 chain