July 2024

Researchers have developed "somersaulting" spin qubits for universal quantum logic. This achievement may enable efficient control of large semiconductor qubit arrays. This is based on two studies published by the research group: a demonstration of "hopping" spins in Nature Communications and their work on "somersaulting" spins in Science. 

In 1998, Loss and DiVincenzo published the seminal work ‘quantum computation with quantum dots’. In their original work, hopping of spins was proposed as a basis for qubit logic, but an experimental implementation remained lacking. After more than 20 years, experiments have caught up with theory. Researchers at QuTech—a collaboration between the TU Delft and TNO—have demonstrated that the original ‘hopping gates’ are indeed possible, with state-of-the-art performance.

Researchers from the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Sorbonne Université CNRS, INRS-EMT, FERMI, Uppsala University, University of York and University of Hull have developed a non-thermal method to alter magnetization using XUV radiation, utilizing the inverse Faraday effect in an iron-gadolinium alloy. This approach enables significant magnetization changes without the usual thermal effects, promising enhancements in ultrafast magnetism technologies. 

Intense laser pulses can be used to manipulate or even switch the magnetization orientation of a material on extremely short time scales. Typically, such effects are thermally induced, as the absorbed laser energy heats up the material very rapidly, causing an ultrafast perturbation of the magnetic order. The research team has now demonstrated an effective non-thermal approach of generating large magnetization changes. By exposing a ferrimagnetic iron-gadolinium alloy to circularly polarized pulses of extreme ultraviolet (XUV) radiation, they could reveal a particularly strong magnetic response depending on the handedness of the incoming XUV light burst (left- or right-circular polarization).

While the field of spintronics tries to leverage the spin angular momentum of electrons to develop new technologies, these particles' orbital momentum has so far been rarely considered. Currently, generating an orbital current (i.e., a flow of orbital angular momentum) remains far more challenging than generating a spin current. Nonetheless, approaches to successfully leveraging the orbital angular momentum of electrons could open the possibility for the development of a new class of devices called orbitronics.

Researchers at Japan's Keio University and Germany's Johannes Gutenberg University have reported the successful generation of an orbital current from magnetization dynamics, a phenomenon called orbital pumping. Their outlines a promising approach that could allow engineers to develop new technologies leveraging the orbital angular momentum of electrons.

Researchers from National Renewable Energy Laboratory (NREL), University of Utah, Université de Lorraine CNRS and University of Colorado Boulder have improved upon their previous work, that included incorporating a perovskite layer that allowed the creation of a new type of polarized light-emitting diode (LED) that emits spin-controlled photons at room temperature without the use of magnetic fields or ferromagnetic contacts. In their latest work, they have gone a step further by integrating a III-V semiconductor optoelectronic structure with a chiral halide perovskite semiconductor.

The team transformed an existing commercialized LED into one that also controls the spin of electrons. The results could provide a pathway toward transforming modern optoelectronics, a field that relies on the control of light and encompasses LEDs, solar cells, and telecommunications lasers, among other devices.

Researchers at MIT, DEVCOM Army Research Laboratory, The Ohio State University, and University of Ottawa have reported unique electron mobility in a new crystal film that could be the basis for wearable thermoelectric and spintronic devices.

A material with a high electron mobility is like a highway without traffic, and the electrons that flow into the material experience movement without any obstacles to slow or scatter them off their path. The higher a material’s electron mobility, the more efficient its electrical conductivity, and the less energy is lost or wasted as electrons move through. Advanced materials that exhibit high electron mobility will be essential for more efficient and sustainable electronic devices that can do more work with less power.