First-order commensurate–incommensurate magnetic phase transition in the coupled FM spin-1/2 two-leg ladders

• Published in: Physica. B, Condensed matter Vol. 476; pp. 24 - 28
• Main Authors: Jahangiri, J., Hadipour, H., Mahdavifar, S., Farjami Shayesteh, S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2015
• Subjects: Condensed matter; Coupled ladder; Ground state; Joining; Ladders; Legs; Magnetic field-phase transition; Magnetic fields; Phase diagrams; Phase transformations; Spin 1/2 two-leg ladder; Thermodynamic behavior; Spin 1/2 two-leg ladder; Coupled ladder; Magnetic field-phase transition; Thermodynamic behavior
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2015.07.012

We consider the spin-1/2 two-leg ladders with ferromagnetic (FM) interactions along legs and rungs. Using the stochastic series expansion QMC method, we study the low-temperature magnetic behavior of the system. An isolated spin-1/2 FM two-leg ladder is in the gapped saturated FM phase at zero temperature. As soon as the spin-1/2 FM two-leg ladders are connected with antiferromagnetic (AFM) inter-ladder interaction, a first-order commensurate–incommensurate quantum phase transition occurs in the ground state magnetic phase diagram. In fact a jump in the magnetization curve is observed. We found that, coupled spin-1/2 FM two-leg ladders are in a nonmagnetic phase at zero temperature. Applying a magnetic field, the ground state of coupled spin-1/2 FM two-leg ladders remains in the nonmagnetic phase up to a quantum saturate critical field.