Researchers achieve room-temperature electron spin polarization exceeding 90% in an opto-spintronic semiconductor nanostructure

A team of researchers from Sweden, Finland and Japan have designed a semiconductor component in which information can be efficiently exchanged between electron spin and light at room temperature and above.

Developments in spintronics in recent decades have been based on the use of metals, and these have been highly significant for the possibility of storing large amounts of data. There would, however, be several advantages in using spintronics based on semiconductors, in the same way that semiconductors form the backbone of today's electronics and photonics.

Researchers discover the existence of elusive spin dynamics in quantum mechanical systems

Researchers from Oak Ridge National Laboratory (ORNL), University of California and Lawrence Berkeley National Laboratory have discovered the existence of elusive spin dynamics in quantum mechanical systems.

The team successfully simulated and measured spins - magnetic particles, which can exhibit a motion known as Kardar-Parisi-Zhang in solid materials at varying temperatures. Up until now, scientists have only found evidence of the spin dynamics in soft matter and other classical materials.

Researchers use unique material to control spin polarization

Researchers used the Advanced Photon Source (APS), a U.S. Department of Energy Office of Science User Facility at DOE’s Argonne National Laboratory, to study ways to manipulate electron spins and develop new materials for spintronics. The research team, led by Chang-Beom Eom at the University of Wisconsin-Madison, designed a new material that has three times the storage density and uses much less power than other spintronics devices.

Not many of these types of materials exist, especially ones that work at room temperature like this one. If the new material can be perfected, it could aid in the creation of more efficient electronic devices with less tendency to overheat. This is particularly important for advancing the development of low-power computing and fast magnetic memory.

University of Groningen team takes a step towards analogue spintronic devices

University of Groningen researchers have measured the presence of electron-spin-dependent nonlinearity in a van der Waals heterostructure spintronic device. The team went on to demonstrate its application for basic analog operations such as essential elements of amplitude modulation and frequency sum (heterodyne detection) on pure spin signals, by exploiting the second-harmonic generation of the spin signal due to nonlinear spin injection.

New discovery brings analogue spintronic devices closer imageGraphene (light green) with boron nitride (blue) on top. Measuring points indicated in orange.

The researchers also showed that the presence of nonlinearity in the spin signal has an amplifying effect on the energy-dependent conductivity-induced nonlinear spin-to-charge conversion effect. The interaction of the two spin-dependent nonlinear effects in the spin-transport channel leads to a highly efficient modulation of the spin-to-charge conversion effect, which in principle can also be measured without using a ferromagnetic detector. These effects are measured both at room and low temperatures, and are suitable for their applications as nonlinear circuit elements in the fields of advanced spintronics and spin-based neuromorphic computing.

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.