Efficient spin detection of photoexcited electrons at room temperature in single ferromagnetic (FM) layer/semiconductor (SC) Schottky barrier structures has recently been demonstrated in our group [1,2]. We find that the photocurrent is dependent on the relative alignment of the light helicity with the FM layer magnetisation and attribute this effect to the spin filtering of electrons at the SC...

The effect of spin mixing due to thermal spin waves and temperature dependence of hot electron spin polarization to the collector current in a spin-valve transistor has been theoretically explored. We calculate the collector current as well as the temperature dependence of magnetocurrent at finite temperatures to investigate the relative importance of spin mixing and hot electron spin polarizat...

We present transport measurements of ferromagnetically contacted carbon nanotubes. In both singleand multi-walled nanotube devices, a spin valve effect is observed due to spin-polarized transport. In one single-walled nanotube device, the spin-valve effect is suppressed as the influence of Coulomb charging is observed at around 10 K. To help understand the interplay between the Coulomb charging...

The magnetoresistance of Ni/V2O3/Py devices shows interesting behavior in the temperature dependence across the V2O3 metal-insulator transition. A spin-valve effect ( 0.1%) is found below the transition temperature when V2O3 is in the insulating phase. Contrary to expectation, the spin-valve effect disappears when device is heated above 150 K and V2O3 is in the metallic state. At these temperat...

The temperature dependence of magneto current in the spin spin valve transistor system is theoretically explored based on phenomenological model. We find that the collector current strongly depends on the relative orientation of magnetic moment of ferromagnetic metals due to spin mixing effect. For example, the collector current is decreasing in the parallel case with increasing temperature, an...

A graphene lateral spin valve structure with asymmetric contacts is presented for the first time, with enhancement of spin angular momentum absorption in its receiving magnet. The asymmetric device with tunneling barrier only at the injector magnet shows a comparable spin valve signal but lower electrical noises compared to the device with two tunneling barriers. We also report experimental mea...

The non-local spin injection in lateral spin valves is strongly expected to be an effective method to generate a pure spin current for potential spintronic application. However, the spin-valve voltage, which determines the magnitude of the spin current flowing into an additional ferromagnetic wire, is typically of the order of 1 μV. Here we show that lateral spin valves with low-resistivity NiF...

for an Invited Paper for the MAR05 Meeting of The American Physical Society Spin Transport in Organic Semiconductors JING SHI, University of Utah Spin injection/detection and coherent transport are necessary ingredients in spin electronics or spintronics. Organic semiconductors are believed to have long spin coherence due to the weak spin-orbit interaction and hyperfine interaction; therefore, ...

The observations of both positive and negative signs in tunneling magnetoresistance (TMR) for the same organic spin-valve structure have baffled researchers working in organic spintronics. In this article, we provide an answer to this puzzle by exploring the role of metal-molecule interface on TMR in a single molecular spin-valve junction. A planar organic molecule sandwiched between two nickel...

We have measured the nonlocal resistance of aluminum-iron spin-valve structures fabricated by e-beam lithography and shadow evaporation. The sample geometry consists of an aluminum bar with two or more ferromagnetic wires forming point contacts to the aluminum at varying distances from each other. In the normal state of aluminum, we observe a spin-valve signal which allows us to control the rel...