61 research outputs found
Cavity optomechanical mass sensor in water with sub-femtogram resolution
Sub-femtogram resolution of an in-liquid cavity optomechanical mass sensor
based on the twin-microbottle glass resonator is demonstrated. An evaluation of
the frequency stability using an optomechanical phase-locked loop reveals that
this cavity optomechanical sensor has the highest mass resolution of
g in water, which is four orders of magnitude
better than that in our first-generation setup [Sci. Adv. 8, eabq2502 (2022)].
This highly sensitive mass sensor provides a free-access optomechanical probe
in liquid and could thus be extended to a wide variety of in-situ chemical and
biological metrology applications
Quadrature skyrmions in two-dimensionally arrayed parametric resonators
Skyrmions are topological solitons in two-dimensional systems and have been
observed in various physical systems. Generating and controlling skyrmions in
artificial resonator arrays lead to novel acoustic, photonic, and electric
devices, but it is a challenge to implement a vector variable with the chiral
exchange interaction. Here, we propose to use quadrature variables, where their
parametric coupling enables skyrmions to be stabilized. A finite-element
simulation indicates that a stable acoustic skyrmion would exist in a realistic
structure consisting of a piezoelectric membrane array.Comment: 22 pages, 10 figure
Cavity magnomechanical coupling with coupled magnon modes in a synthetic antiferromagnet
On-chip cavity magnomechanics is an emerging field exploring acoustic and
magnonic functionalities of various ferromagnetic materials and structures
using strongly confined phonons. It is expected that such cavity magnomechanics
can be extended to multilayer ferromagnets, especially synthetic
antiferromagnets (SAFs) that exhibit zero net magnetization through interlayer
exchange coupling. However, the conventional theoretical framework for a single
ferromagnet cannot be used directly because of the antiferromagnetic
magnetization dynamics associated with the interlayer exchange coupling. In
this paper, we theoretically investigate phonon-magnon coupling with a
three-layer SAF. Our formulation of the phonon-magnon coupling constants
reveals that the acoustic (optical) magnon mode dominantly couples to the
cavity phonon when the magnetization angles in the two ferromagnetic layers are
antiparallel (orthogonal). Moreover, numerical calculations including the
effects of dipole-dipole interactions and in-plane uniaxial magnetic anisotropy
allow us to predict phonon frequency shifts and linewidth broadening that can
be detected in experiments. These theoretical insights would greatly help us to
make a strategy for bringing the system into the strong coupling regime and to
devise novel control protocols in analogy to cavity quantum electrodynamics and
cavity optomechanics
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