A Quantum Tango between Magnons and Phonons

American Physical Society  October 26, 2020 A magnon polaron, hybridized state of a phonon and a magnon, can be formed at the intersection of the magnon and phonon dispersions, where their frequencies coincide. However, the weak interaction of magnons and phonons and their short lifetimes jeopardize the strong coupling required for the formation of a hybridized state. An international team of researchers (Germany, Russia, Ukraine, UK) overcame these limitations by spatial matching of magnons and phonons in a metallic ferromagnet with a nanoscale periodic surface pattern. The spatial overlap results in a high coupling strength which, in combination with their […]

Integrated circuit of pure magnons

Nanowerk  October 20, 2020 Magnons have been used to encode information in computing applications, and magnonic device components, including logic gates, transistors, and units for non-Boolean computing. Magnonic directional couplers, which can function as circuit building blocks have been impractical because of their millimetre dimensions and multimode spectra. An international team of researchers (Austria, Ukraine, Germany, Belgium, the Netherlands) has developed a magnonic directional coupler based on yttrium iron garnet that has submicrometre dimensions. The coupler consists of single-mode waveguides with a width of 350 nm. They used the amplitude of a spin wave to encode information and to guide it […]

Using magnetic worms to engineer nanoscale communication systems

Nanowerk  July 15, 2020 High-frequency electromagnetic waves are used to transmit and process information in microelectronic devices. To gain a better understanding of precisely the way magnons behave and propagate in different structures researchers in Switzerland examined how electromagnetic waves propagate, and how they could be manipulated, in artificial ferromagnetic quasicrystals. They found that under controlled conditions a single electromagnetic wave coupled to an artificial quasicrystal splits into several spin waves which then propagate within the structure. Each of these spin waves represents a different phase of the original electromagnetic wave, carrying different information. By imaging wavefronts in quasicrystals, insight […]

Researchers find potential solution to overheating mobile phones

Phys.org  November 29, 2019 Widespread applications of magnetic devices require an efficient means to manipulate the local magnetization. An international team of researchers (Singapore, South Korea) has experimentally demonstrated an alternative approach based on magnon currents and achieved magnon-torque–induced magnetization switching in Bi2Se3/antiferromagnetic insulator NiO/ferromagnet devices at room temperature. The magnon currents carry spin angular momentum efficiently without involving moving electrons through a 25-nanometer-thick NiO layer. The magnon torque is sufficient to control the magnetization. This research, which is relevant to the energy-efficient control of spintronic devices, will invigorate magnon-based memory and logic devices…read more. TECHNICAL ARTICLE 

Magnonic devices can replace electronics without much noise

Phys.org  March 4, 2019 Researchers at UC Riverside created a chip that generated spin wave between transmitting and receiving antennae. They showed that the low-frequency noise of magnonic devices is dominated by the random telegraph signal noise rather than 1/f noise. It was also found that the noise level of surface magnons depends strongly on the power level, increasing sharply at the on-set of nonlinear dissipation. The presence of the random telegraph signal noise suggests that the current fluctuations involve random discrete macro events caused by an individual macro-scale fluctuator. The findings may help in developing the next generation of […]