Hall Effect In Magnetic Films Research Articles

Non-volatile logic gates based on planar Hall effect in magnetic films with two in-plane easy axes

We discuss the use of planar Hall effect (PHE) in a ferromagnetic GaMnAs film with two in-plane easy axes as a means for achieving novel logic functionalities. We show that the switching of magnetization between the easy axes in a GaMnAs film depends strongly on the magnitude of the current flowing through the film due to thermal effects that modify its magnetic anisotropy. Planar Hall resistance in a GaMnAs film with two in-plane easy axes shows well-defined maxima and minima that can serve as two binary logic states. By choosing appropriate magnitudes of the input current for the GaMnAs Hall device, magnetic logic functions can then be achieved. Specifically, non-volatile logic functionalities such as AND, OR, NAND, and NOR gates can be obtained in such a device by selecting appropriate initial conditions. These results, involving a simple PHE device, hold promise for realizing programmable logic elements in magnetic electronics.

Programmable Spin Logic Based on Spin Hall Effect in a Single Device

Spin logic devices, due to their programmability and nonvolatility, are deemed as an ideal building block for the next generation of electronics. Though several types of spin logic based on domain wall motion, spin‐field‐effect transistor and automata made of magnetic nanoparticles have been proposed, an architecture with scalability, energy efficiency and compatibility with current complementary metal‐oxide‐semiconductor technology is still in urgent demand. Here, it is experimentally demonstrated that the spin Hall effect in magnetic films with perpendicular anisotropy can be utilized to construct such a spin logic device. Five commonly used logic gates with nonvolatility in a single device are realized. This demonstration could pave the way towards application of spintronics in logic circuits as well as the memory industry in the near future and could even give birth to logic‐in‐memory computing architectures.

Extraordinary Hall effect in magnetic films

We review some of the recent developments in the studies of the extraordinary Hall effect in magnetic films. Three major topics are discussed: (1) physics and characterization of the effect in heterogeneous and geometrically confined magnetic systems, (2) use of the effect as a tool for the study of ultra-thin films and nanoscopic magnetic objects, and (3) potential technical applications for magnetic sensors and memory devices.