Interplay between Magnetic and Vestigial Nematic Orders in the Layered - Classical Heisenberg Model
arXiv:1901.07234 · doi:10.1103/PhysRevB.99.174404
Abstract
We study the layered - classical Heisenberg model on the square lattice using a self-consistent bond theory. We derive the phase diagram for fixed as a function of temperature , and interplane coupling . Broad regions of (anti)ferromagnetic and stripe order are found, and are separated by a first-order transition near (in units of ). Within the stripe phase the magnetic and vestigial nematic transitions occur simultaneously in first-order fashion for strong . For weaker there is in addition, for , an intermediate regime of split transitions implying a finite temperature region with nematic order but no long-range stripe magnetic order. In this split regime, the order of the transitions depends sensitively on the deviation from and , with split second-order transitions predominating for . We find that the value of depends weakly on the interplane coupling and is just slightly larger than for . In contrast the value of increases quickly from at as the interplane coupling is further reduced. In addition, the magnetic correlation length is shown to directly depend on the nematic order parameter and thus exhibits a sharp increase (or jump) upon entering the nematic phase. Our results are broadly consistent with predictions based on itinerant electron models of the iron-based superconductors in the normal-state, and thus help substantiate a classical spin framework for providing a phenomenological description of their magnetic properties.
arXiv comment13 pages, 20 figures
References in corpus (17)
- Superconductivity in Iron Compounds
- High-temperature superconductivity in iron-based materials
- Nematic order in iron superconductors - who is in the driver's seat?
- Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
- Theory of Electron Nematic Order in LaOFeAs
- Magnetism and its microscopic origin in iron-based high-temperature superconductors
- Origin of the ~150 K Anomaly in LaOFeAs; Competing Antiferromagnetic Superexchange Interactions, Frustration, and Structural Phase Transition
- Critical exponents and equation of state of the three-dimensional Heisenberg universality class
- Ising and Spin orders in Iron-based Superconductors
- Preemptive nematic order, pseudogap, and orbital order in the iron pnictides
- Antiferromagnetic superexchange interactions in LaOFeAs
- Critical level crossings and gapless spin liquid in the square-lattice spin- - Heisenberg antiferromagnet
- Electronic Structure of Fe-Based Superconductors
- Ising transition driven by frustration in a 2D classical model with SU(2) symmetry
- On a Renormalization Group Approach to Dimensional Crossover
- Dimensional crossover in the quasi-two-dimensional Ising-O(3) model
- Nematic Bond Theory of Heisenberg Helimagnets