Nonlinear phononic control and emergent magnetism in Mott insulating titanates

Article

关键词: ELECTRONIC-STRUCTURE;    OXIDE;    TRANSITION;    PHASE;    SUPERCONDUCTIVITY;    LOCALIZATION;    PEROVSKITES;    DYNAMICS;    SPECTRA;   

DOI  :  10.1103/PhysRevB.98.024102

来源: SCIE

【 摘 要 】

Optical control of structure-driven magnetic order offers a platform for magneto-optical terahertz devices. We control the magnetic phases of d(1) Mott insulating titanates using nonlinear phononics to transiently perturb the atomic structure based on density functional theory (DFT) simulations and solutions to a lattice Hamiltonian including nonlinear multimode interactions. We show that magnetism is tuned by indirect excitation of a Raman-active phonon mode, which affects the amplitude of the TiO6 octahedral rotations that couple to static Ti-O Jahn-Teller distortions, through driven infrared-active modes of LaTiO3 and YTiO3 . The mode excitation reduces the rotational angle, driving a magnetic phase transition from a ferromagnetic (FM) to G-type antiferromagnetic (AFM) state. A novel A-type AFM state hidden in the bulk equilibrium phase diagram emerges as a dynamically accessible optically induced phase under multimode excitations. Our work shows that nonlinear phononics can stabilize phases inaccessible to static chemical substitutions or lattice strains.

【 授权许可】

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