We devised a method to measure the virtual magnetic field induced by Rashba effect in ferromagnetic metal layer. Transverse Rashba magnetic field makes the magnetization direction tilted out of the easy axis, which could be detected by the change in anomalous hall resistances. Through a specified measurement of the second harmonics of the hall resistance, the Rashba field could be obtained with high sensitivity even at low current regime. The results are compared with the prior reports based on the measurement of the transverse field required for the nucleation of reversed domain.

Applying magnetic exchange force microscopy with an Fe-coated tip, we experimentally resolve the atomic-scale antiferromagnetic structure of the Fe monolayer on W(001). On the basis of first-principles calculations, using an Fe nanocluster as a tip, we determine the distance dependence of the magnetic exchange forces. Significant relaxation of tip and sample atoms occurs, which depend sensitively on the local magnetic configuration. This shifts the onset of magnetic interactions toward larger separations and facilitates their observation. Implementing a multiatom tip in the calculations and accounting for relaxation effects are crucial to obtain the correct sign and distance dependence of the magnetic exchange interaction. By comparison with our calculations, we show that the experimentally observed contrast is due to a competition between chemical and magnetic forces.

The electrical responses of vanadium pentoxide nanowires to helium gas and environmental pressures are demonstrated. The devices feature well-aligned nanowires that are oriented by electrophoresis technique in the submicron scale. The electrical conductance is found to increase and decrease upon exposure to helium gas and air, respectively. This electrical response to helium is due to physical adsorption of the helium atoms into the interlayer of vanadium pentoxide nanowires. Furthermore, we observe flow-rate-dependent conductance variations such that the conductance is increased with stepwise behavior to the increase of flow rate of helium.

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We report first-principles calculations on the magnetocrystalline anisotropy energy (MAE) of an Fe monolayer sandwiched by MgO. We found that by increasing the interlayer distance between Fe and O by about 8% from its equilibrium value, the perpendicular interfacial magnetic anisotropy can be enhanced as high as 2.75 erg/cm2, which is three times larger than that at the equilibrium distance. The analysis of MAE based on the second-order interactions of the spin-orbit coupling shows that the energy position of the majority-spin dz2 orbital is of central importance in determining MAE. Our results suggest that increasing the Fe–O distance in the Fe/MgO system is an important material-design direction for high-performance magnetic memories.