Ultrafast Double Pulse All-Optical Reswitching of a Ferrimagnet.

All-optical reswitching has been investigated in the half-metallic Heusler ferrimagnet Mn_{2}Ru_{0.9}Ga, where Mn atoms occupy two inequivalent sites in the XA-type structure. The effect of a second 200 fs, 800 nm laser pulse that follows the first pump pulse, when both are above the threshold for switching, is studied as a function of t_{12}, the time between them.

Sub-picosecond exchange-relaxation in the compensated ferrimagnet MnRuGa.

We study the demagnetization dynamics of the fully compensated half-metallic ferrimagnet MnRuGa. While the two antiferromagnetically coupled sublattices are both composed of manganese, they exhibit different temperature dependencies due to their differing local environments. The sublattice magnetization dynamics triggered by femtosecond laser pulses are studied to reveal the roles played by the spin and intersublattice exchange.

Helium Ion Microscopy for Reduced Spin Orbit Torque Switching Currents.

Spin orbit torque driven switching is a favorable way to manipulate nanoscale magnetic objects for both memory and wireless communication devices. The critical current required to switch from one magnetic state to another depends on the geometry and the intrinsic properties of the materials used, which are difficult to control locally. Here, we demonstrate how focused helium ion beam irradiation can modulate the local magnetic anisotropy of a Co thin film at the microscopic scale.

Single pulse all-optical toggle switching of magnetization without gadolinium in the ferrimagnet MnRuGa.

Energy-efficient control of magnetization without the help of a magnetic field is a key goal of spintronics. Purely heat-induced single-pulse all-optical toggle switching has been demonstrated, but so far only in Gd-based amorphous ferrimagnet films. In this work, we demonstrate toggle switching in films of the half-metallic ferrimagnetic Heusler alloys MnRuGa, which have two crystallographically-inequivalent Mn sublattices.

Effect of insertion layer on electrode properties in magnetic tunnel junctions with a zero-moment half-metal.

Due to its negligible spontaneous magnetization, high spin polarization and giant perpendicular magnetic anisotropy, MnRuGa (MRG) is an ideal candidate as an oscillating layer in THz spin-transfer-torque nano-oscillators. Here, the effect of ultrathin Al and Ta diffusion barriers between MRG and MgO in perpendicular magnetic tunnel junctions is investigated and compared to devices with a bare MRG/MgO interface. Both the compensation temperature, T, of the electrode and the tunneling magnetoresistance (TMR) of the device are highly sensitive to the choice and thickness of the insertion layer used.