Room Temperature - Page 2

Researchers from the Energy Department’s National Renewable Energy Laboratory (NREL), quite accidentally, discovered that perovskite materials, grown using solution processing, exhibit the optical Stark effect at room temperatures.

The NREL team used the Stark effect to remove the degeneracy of the excitonic spin states within the perovskite sample. The optical Stark effect can be used to create promising technologies, including the potential to be used as an ultrafast optical switch. In addition, it can be used to control or address individual spin states, which is needed for spin-based quantum computing.

Researchers from MIT and colleagues from the US, Germany France and India discovered that when you combine a topological insulator (bismuth selenide) with a magnetic material (europium sulfide) you create a material that one can can control its magnetic properties. The new material retains the electronic property of the topological insulator and also the full magnetization capabilities of the magnetic material.

The researchers were surprised by the stability of that effect - in fact the material exhibited those great properties at room temperatures, which means that this hybrid material can be used to create spintronics devices.

Researchers from Japan and Vietnam report an iron-doped ferromagnetic semiconductors at room temperature. They say this is the same time that a ferromagnetic semiconductor is demonstrated, which is seen as a promising spintronic device material.

The researchers say that current theory predicted that a type of semiconductor known as "wide band gap" would be strongly ferromagnetic, and most research focused on that approach. But the researchers chose a narrow-gap semconductor (both indium arsenide and gallium antimonide were chosen) as the host semiconductor, which enabled them to obtain ferromagnetism and conserve it at room temperature by adjusting doping concentrations.

Researchers from the U.S. Naval Research Laboratory (NRL) developed a new type of room-temperature tunnel device structure in which the tunnel barrier and transport channel are both made of graphene.

In this new design, hydrogenated graphene acts as a tunnel barrier on another layer of graphene for charge and spin transport. The researchers demonstrated spin-polarized tunnel injection through the hydrogenated graphene, and lateral transport, precession and electrical detection of pure spin current in the graphene channel. The team sasy that the spin polarization values are higher than those found using more common oxide tunnel barriers, and spin transport at room temperature.

Researchers from the University of Chicago managed to line-up nuclear spins in a consistent and controllable way, on silicon-carbide, a high-performance and practical material. The technique uses light to polarize the spins - and is performed at room temperature.

Nuclear spins are normally randomly oriented, and the known methods of aligning them are complicated - and not entirely reliable. This is mostly because the spin of a nucleus is tiny - about 1,000 times smaller than the spin of an electron. The new technique is relatively simple and manages to align the spin of more than 99% spins in a Silicon Carbide nuclei.

Researchers from Korea discovered that making a thin film of multiferroic material bismuth ferrite improved the material's electric and magnetic properties. Bismuth Ferrite works as a spintronics material at room temperature, and this film is flexible - which could lead to flexible spintronics devices.

To create the film, the researchers used bismuth ferrite nanoparticles (about 24nm in size) mixed in a polymer solution and then dried - which resulted in a flexible and slightly-stretchable film. The thin film kept its improved electric and magnetic properties even when bent into a cylinder.

Two independent studies published recently suggest that Silicon Carbide (SiC) is a promising material for atomic-scale spintronics. Both reported their results in Nature Materials.

The first study (by researchers from the University of Chicago, the University of California, Linkoping University, and the Japan Atomic Energy Agency) shows that individual electron spins in high-purity monocrystalline 4H-SiC can be isolated and coherently controlled. These states exhibit exceptionally long ensemble Hahn-echo spin coherence times, exceeding 1ms.

Researchers from the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Cornell University managed to use an electric field to reverse the magnetization direction in a multiferroic spintronic device at room temperature.

The researchers showed that 180-degree magnetization switching in the multiferroic bismuth ferrite can be achieved at room temperature with an external electric field when the kinetics of the switching involves a two-step process. They say that this demonstration, which runs counter to conventional scientific wisdom, points a new way towards spintronics applications.

Researchers from the University of Utah have managed to control and read spin information at room temperatures. For this experiment, they used an orange OLED device.

The researchers were able to read the nuclear spins of two hydrogen isotops: a single proton and deuterium (a proton, neutron and electron). When the researchers controlled the spin, they controlled the electrical current in the device.

Researchers from the Johannes Gutenberg University Mainz (JGU) managed to directly observe the 100% spin polarization of a Heusler compound. A Heusler alloy is made from several metallic elements arranged in a lattice structure, and the researchers used the compound Co₂MnSi. This paves the way towards using Heusler materials for spintronics devices.

Spin polarization is the degree of parallel orientation of the spins of the electrons that transport the charge. The ideal spintronics material has the maximum possible spin polarization. The Heusler alloy used in this material was shown to have an almost complete spin polarization at room temperature.