Room Temperature | Spintronics-Info

Researchers design a spin-engine that uses spintronics to harvest energy from heat at room temperatures

An international team of researchers from France and Sweden designed a new concept of an energy harvesting engine based on spintronics and quantum thermodynamics. The basic idea is to use electron spin to harvest thermal fluctuations at room temperature.

Spin-polarized energy landscape of the spin-engine photo

The researchers make use of the fact that paramagnetic centers, or atom-level magnets, fluctuate their spin orientation due to heat. In the so called spin-engine, the a spontaneous bias voltage V appears between the electrodes, and thus a spontaneous current flows once the electrical circuit is closed.

There are still many challenges to create such devices (the team made some initial experiments) - but the researchers say that this concept could create chips that continuously produce electrical power with a power density that is 3x greater than raw solar irradiation on Earth.

Will perovskites hold the key to spin-based quantum computing?

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.

Proximity-induced magnetism promising for room-temperature spintronics

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.

Ferromagnetic insulator and topological insulator (MIT)

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.

Iron-doped ferromagnetic semiconductors at room temperature

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.

New room-temperature tunnel device developed using graphene as tunnel barrier and transport channel

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.

NRL scientists use graphene as tunnel barrier for spintronics image

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.

Researcher use light to consistently control the nuclear spins of silicon-carbide

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.

Korean researchers managed to create a flexible film suitable for spintronics applications

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.

Researchers show SiC is a promising spintronics material

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, Linköping 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.

Berkeley Lab Reports on Electric Field Switching of Ferromagnetism at Room Temp

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.

Berkeley Lab Electric-Field Switching of Ferromagnetism render

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.

Reading and controlling nuclear spin on plastic electronic devices at room temperature

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.