Extraordinary magnetic response of an anisotropic 2D antiferromagnet via site-dilution

Abstract

A prominent character of two-dimensional magnetic systems is the enhanced spin fluctuations, which however reduce the ordering temperature. Here we report that a magnetic field of only one-thousandth of the Heisenberg superexchange interaction can induce a crossover, which for practical purposes is the effective ordering transition, at temperatures about 6 times of the Neel transition in a site-diluted two-dimensional anisotropic quantum antiferromagnet. Such a strong magnetic response is enabled because the system directly enters the antiferromagnetically ordered state from the isotropic disordered state skipping the intermediate anisotropic stage. The underlying mechanism is achieved on a pseudospin-half square lattice realized in the [(SrIrO3)1/(SrTiO3)2] superlattice thin film that is designed to linearly couple the staggered magnetization to external magnetic fields by virtue of the rotational symmetry-preserving Dzyaloshinskii Moriya interaction. Our model analysis shows that the skipping of the anisotropic regime despite the finite anisotropy is due to the enhanced isotropic fluctuations under moderate dilution.

References in corpus (9)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Magnetic 2D materials and heterostructures
• Twisted Hubbard Model for Sr2IrO4: Magnetism and Possible High Temperature Superconductivity
• Magnetic Skyrmion Bundles and Their Current-Driven Dynamics
• Electrical manipulation of skyrmions in a chiral magnet
• Detection of XY behaviour in weakly anisotropic quantum antiferromagnets on the square lattice
• The Two-Dimensional Square-Lattice S=1/2 Antiferromagnet Cu(pz)${}_2$(ClO${}_4$)${}_2$
• Field-induced XY behavior in the S=1/2 antiferromagnet on the square lattice
• Anomalous Magnetoresistance due to Longitudinal Spin Fluctuations in a Jeff = 1/2 Mott Semiconductor