Optically induced ultrafast magnetization switching in ferromagnetic spin valves.

The discovery of spin-transfer torque (STT) enabled the control of the magnetization direction in magnetic devices in nanoseconds using an electrical current. Ultrashort optical pulses have also been used to manipulate the magnetization of ferrimagnets at picosecond timescales by bringing the system out of equilibrium. So far, these methods of magnetization manipulation have mostly been developed independently within the fields of spintronics and ultrafast magnetism.

Field-Free Magnetoplasmon-Induced Ultraviolet Circular Dichroism Switching in Premagnetized Magnetic Nanowires.

Broadband modulation of magnetic circular dichroism (MCD) using a relatively low magnetic field or by producing a field-free magnetoplasmonic effect in the remnant magnetic state was achieved by the integration of the noble metals (NMs) Au and Ag and the perpendicular magnetic anisotropy of Co with ZnO nanowires (NWs) used as the template. The samples containing NMs revealed MCD sign reversals and enhancements when compared with the original Co/ZnO NWs. The magnetoplasmonic effect of Au close to the visible light spectrum could induce the CD change in the visible region.

Enhanced Photodegradation in Metal Oxide Nanowires with Co-Doped Surfaces under a Low Magnetic Field.

This work demonstrated the enhanced photodegradation (PD) resulting from Co-rich doping of ZnO nanowire (NW) surfaces (Co/ZnO NWs) prepared by combining Co sputtering on ZnO NWs and immersion in deionized water to exploit the hydrophilic-hydrophobic transitions on the ZnO surfaces resulting from Co atom diffusion. Because of the controllable spin-dependent density of states (DOS) induced by Co, the PD of methylene blue dye can be enhanced by approximately 90% (when compared with bare ZnO NWs) by using a conventional permanent magnet with a relatively low magnetic field strength of approximately 0.15 T.

Strong Excitonic Magneto-Optic Effects in Two-Dimensional Organic-Inorganic Hybrid Perovskites.

This work demonstrates the strong excitonic magneto-optic (MO) effects of magnetic circular dichroism (MCD) and Faraday rotation (FR) in nonmagnetic two-dimensional (2D) organic-inorganic hybrid Ruddlesden-Popper perovskites (RPPs) at room temperature. Due to their strong and sharp excitonic absorption as a result of unique quantum well structures of 2D RPPs, sizeable linear excitonic MO effects of MCD and FR can be observed at room temperature under a low magnetic field (<1 T) compared with their three-dimensional counterpart. In addition, since the band gaps of 2D organic-inorganic hybrid perovskites can be manipulated either by changing the number of inorganic octahedral slabs per unit cell or through halide engineering, linear excitonic MO effects of 2D-RPPs can be observed through the broadband spectral ranges of visible light.

Giant Zeeman Splitting for Monolayer Nanosheets at Room Temperature.

Giant Zeeman splitting and zero-field splitting (ZFS) are observed in 2D nanosheets that have monolayers of atomic thickness. In this study, single-crystalline CdSe(ethylenediamine) and Mn-doped nanosheets are synthesized via a solvothermal process. Tunable amounts of Mn(0.

Manipulated Optical Absorption and Accompanied Photocurrent Using Magnetic Field in Charger Transfer Engineered C/ZnO Nanowires.

The rarely explored, spin-polarized band engineering, enables direct dynamic control of the magneto-optical absorption (MOA) and associated magneto-photocurrent (MPC) by a magnetic field, greatly enhancing the range of applicability of photosensitive semiconductor materials. It is demonstrated that large negative and positive MOA and MPC effects can be tuned alternately in amorphous carbon ( )/ZnO nanowires by controlling the sp/sp ratio of . A sizeable enhancement of the MPC ratio (≈15%) appears at a relatively low magnetic field (≈0.