Terahertz Crystal-Field Transitions and Quasi Ferromagnetic Magnon Excitations in a Noncollinear Magnet for Hybrid Spin-Wave Computation.

The complexity of interactions between the crystal-field and unusual noncollinear spin arrangement in nontrivial magnets demands novel tools to unravel the mystery underneath. In this work, we study such interaction dynamics of crystal-field excitations (CFE) and low-energy magnetic excitations in orthochromite TmCrO with controls of temperature and magnetic field using high-resolution magneto-terahertz (THz) time-domain spectroscopy. The THz energy spectrum spanning 0.

Digital- to Analog-Type Terahertz Modulation Controlled by Mosaicity of the Substrate Template in Rare-Earth Nickelate Thin Films.

The extreme sensitivity of the metal-insulator (M-I) transition in RNiO (R = rare-earth ion) nickelates to various extrinsic and intrinsic factors rely on mechanisms driving structure-property relations. Here, we demonstrate a unique way to control the M-I transition of epitaxial PrSmNiO thin films using a mosaic template of the LaAlO(100) substrate; two sets of epitaxial films were deposited on highly oriented crystals and mosaic (with multiple crystallites) crystals. While the former films exhibit a robust and sharp M-I transition, the films on the mosaic substrate show distinctively much more subtle and broad transition, albeit same factors suggesting compositional purity.

Surface Electronic States Induced High Terahertz Conductivity of CoO Microhollow Structure.

Herein, we report the observation of unusual electronic and magnetic phases in traditional antiferromagnetic CoO micromaterials and modulation of their properties on a temperature scale. In particular, we demonstrate a comparative low-energy carrier dynamics of CoO microflower and microhollow flower (MHF) structures of same average size of 2 μm to unravel the ground-state information induced by surface electronics across the insulator-semiconductor transition using terahertz (THz) time domain spectroscopy. Interestingly, the THz optical constants of these structures are found to exhibit remarkably distinct features both as a function of frequency and temperature.

Electronic control of interface ferromagnetic order and exchange-bias in paramagnetic-antiferromagnetic epitaxial bilayers.

The hetero-epitaxially engineered magnetic phases, formed due to entanglement of the spin, charge and lattice degrees of freedom, at the atomically sharp interfaces of complex oxide heterostructures are indispensable for devising multifunctional devices. In the quest for novel and superior spintronics functionalities, we have explored the interface magnetism in the epitaxial bilayer of atypical magnetic and electronic states, i.e.