Phys.org March 29, 2024 An international team of researchers (Japan, Austria, Spain) observed strong coupling between magnons and surface acoustic wave (SAW) phonons in a thin CoFeB film constructed in an on-chip SAW resonator by analyzing SAW phonon dispersion ant crossings. They used a nanostructured SAW resonator design that allowed them to enhance shear-horizontal strain. This type of strain couples strongly to magnons. Their device design provided the tunability of the film thickness with a fixed phonon wavelength, which was a departure from the conventional approach in strong magnon-phonon coupling research. They detected a monotonic increase in the coupling strength […]
Tag Archives: Phonons
Photon-phonon breakthrough
Science Daily October 8, 2021 By combining the strong coupling between topological photons with phonons in hexagonal boron nitride (hBN), researchers at the City College of New York demonstrated a platform to control and guide hybrid states of light and lattice vibrations. The observed topological edge states of phonon-polaritons are found to carry nonzero angular momentum locked to their propagation direction, which enables their robust transport. Thus, these topological quasiparticles enable the funneling of infrared phonons mediated by helical infrared photons along arbitrary pathways and across sharp bends. This opens opportunities for applications ranging from Raman and vibrational spectroscopy with […]
A peculiar state of matter in layers of semiconductors
MIT News August 19, 2021 Experimental realization of many-body localization (MBL) in solid-state systems has remained challenging. A team of researchers in the US (MIT, Argonne National Laboratory, Brookhaven National Laboratory, University of Wisconsin, Oak Ridge National Laboratory, UC Santa Barbara, University of Pennsylvania) reports evidence of a possible phonon MBL phase in disordered GaAs/AlAs superlattices. Through grazing-incidence inelastic X-ray scattering, they observed a strong deviation of the phonon population from equilibrium in samples doped with ErAs nanodots at low temperature, signaling a departure from thermalization. This behavior occurs within finite phonon energy and wavevector windows, suggesting a localization-thermalization crossover. […]
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 […]
Engineers using soundwaves to search through big data with more stability and ease
Phys.org September 19, 2019 Using three aluminum rods, enough epoxy to connect them and some rubber bands for elasticity researchers at the University of Arizona have demonstrated the possibility for acoustic waves in a classical environment to do the work of quantum information processing without the time limitations and fragility. They sent a wave of sound vibrations down the rods, then monitored two degrees of freedom of the waves: what direction the waves moved down the rods and how the rods moved in relation to one another. To excite the system into a nonseparable state, they identified a frequency at […]
A phonon laser operating at an exceptional point
Phys.org July 20, 2018 Exceptional points (EP) are singularities in the energy functions of a physical system at which two light modes coalesce to produce unusual effects. Understanding the mechanisms responsible for linewidth broadening will enable laser resources with new capabilities. An international of researchers led by the US used an optomechanical system with two coupled silica whispering-gallery-mode microresonators to exploit the interplay between gain and loss to tune a phonon laser to an EP. The team provided direct experimental evidence to show complete overlap of optical supermodes at EP, and that EP-enhanced optical noise can be transferred directly to […]
Tunable diamond string may hold key to quantum memory
Science Daily May 22, 2018 The uncontrolled interaction of a quantum system with its environment is detrimental for quantum coherence. An international team of researchers (USA – Harvard University, Sandia National Laboratory, UK) used a nano-electro-mechanical system to mitigate the effect of thermal phonons on a spin qubit, the silicon vacancy color center, without changing the system temperature. By controlling the strain environment of the colour centre, they tuned its electronic levels to probe, control, and eventually suppress the interaction of its spin with the thermal bath. Strain control provided both large tunability of the optical transitions and significantly improved […]