August 2024

Researchers from the University of California - Riverside, National Institute of Standards and Technology, Massachusetts Institute of Technology and Rigaku Americas have developed a new superconductor material that could potentially be used in quantum computing and be a candidate 'topological superconductor.'

A topological superconductor uses a delocalized state of an electron or hole (a hole behaves like an electron with positive charge) to carry quantum information and process data in a robust manner. The researchers reported in their recent work that they combined trigonal tellurium with a surface state superconductor generated at the surface of a thin film of gold. Trigonal tellurium is a chiral material, which means it cannot be superimposed on its mirror image, like our left and right hands. Trigonal tellurium is also non-magnetic. Nonetheless, the researchers observed quantum states at the interface that host well-defined spin polarization. The spin polarization allows the excitations to be potentially used for creating a spin quantum bit -- or qubit.

Researchers from ETH Zurich recently developed a method to control the quantum states of single electron spins using spin-polarized currents, which could enhance quantum computing technologies. The new technique offers more precise, localized control compared to traditional methods using electromagnetic fields, potentially improving the manipulation of quantum states in devices like qubits. 

Control over quantum systems is typically achieved by time-dependent electric or magnetic fields. Alternatively, electronic spins can be controlled by spin-polarized currents. In their recent work, the team demonstrated coherent driving of a single spin by a radiofrequency spin-polarized current injected from the tip of a scanning tunneling microscope into an organic molecule. With the excitation of electron paramagnetic resonance, the scientists established dynamic control of single spins by spin torque using a local electric current. In addition, their work highlights the dissipative action of the spin-transfer torque, in contrast to the nondissipative action of the magnetic field, which allows for the manipulation of individual spins based on controlled decoherence.

Researchers at India's Institute of Nano Science and Technology (INST), an autonomous research institution of Department of Science and Technology (DST), recently produced a transparent conducting interface between two insulating materials with room temperature spin polarized electron gas, which allows for see-through devices with efficient spin currents. 

Prof. Suvankar Chakraverty and his group at INST have produced a 2D Electron Gas (2DEG) with room temperature spin polarization at the interface composed of chemicals LaFeO₃ and SrTiO₃. They grew super lattices and hetero structures of oxide materials to realize new and exotic two-dimensional electron gas at the interface of two insulating oxides that could be useful for next generation quantum devices.

Researchers at the University of Tübingen, Helmholtz-Zentrum Berlin, University of Nebraska and Trinity College have used a very thin layer of radicals, 10000 times thinner than a human hair, to coat a ferromagnetic material, polycrystalline cobalt, to change the magnetic properties of cobalt at the junction with the radicals.

Purely organic radicals are a family of molecules composed only of light elements, such as carbon, nitrogen, and oxygen. They are transparent, light, and flexible materials. They promise lower costs of production and sustainable, and recyclable chemistry. These radicals are organic molecules that carry an unpaired electron, i.e., they are materials with permanent magnetic properties. They must be used as a film in a device, i.e., the radical molecules cover a substrate such as a metal surface, forming a coating.