Bicollinear Antiferromagnetic Order, Monoclinic Distortion, and Reversed Resistivity Anisotropy in FeTe as a Result of Spin-Lattice Coupling.
The bicollinear antiferromagnetic order experimentally observed in FeTe is shown to be stabilized by the coupling g[over ˜]_{12} between monoclinic lattice distortions and the spin-nematic order parameter with B_{2g} symmetry, within a three-orbital spin-fermion model studied with Monte Carlo techniques. A finite but small value of g[over ˜]_{12} is required, with a concomitant lattice distortion compatible with experiments, and a tetragonal-monoclinic transition strongly first order. Remarkably, the bicollinear state found here displays a planar resistivity with the "reversed" puzzling anisotropy discovered in transport experiments. Orthorhombic distortions are also incorporated, and phase diagrams interpolating between pnictides and chalcogenides are presented. We conclude that the spin-lattice coupling we introduce is sufficient to explain the challenging properties of FeTe.
Department of Physics and Astronomy,University of Tennessee, Knoxville, Tennessee 37966, USA and Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Christopher B
CB
Bishop
Department of Physics and Astronomy,University of Tennessee, Knoxville, Tennessee 37966, USA and Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Adriana
A
Moreo
Department of Physics and Astronomy,University of Tennessee, Knoxville, Tennessee 37966, USA and Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Elbio
E
Dagotto