129 citations · 270 across the 12 of their papers we have counts for
12 papers
Coherent response of inhomogeneously broadened and spatially localized emitter ensembles in waveguide QED
Lewis Ruks, Xuejun Xu, Ryuichi Ohta +2
Spectrally and spatially varying ensembles of emitters embedded into waveguides are ever-present in both well-established and emerging technologies. If control of collective excita…
Observation of Acoustically Induced Dressed States of Rare-Earth Ions
Ryuichi Ohta, Gregoire Lelu, Xuejun Xu +9
Acoustically induced dressed states of long-lived erbium ions in a crystal are demonstrated. These states are formed by rapid modulation of two-level systems via strain induced by…
Impedance-matched High-overtone Bulk Acoustic Resonator
Megumi Kurosu, Daiki Hatanaka, Ryuichi Ohta +3
A high-overtone bulk acoustic resonator (HBAR), in which a piezoelectric transducer is set on an acoustic cavity, has been attracting attention in both fundamental research and RF…
Rare-earth-mediated opto-mechanical system in the reversed dissipation regime
Ryuichi Ohta, Loïc Herpin, Victor M. Bastidas +3
Strain-mediated interaction between phonons and telecom photons is demonstrated using excited states of erbium ions embedded in a mechanical resonator. Owing to the extremely long-…
Optically probing Schwinger angular momenta in a micromechanical resonator
Motoki Asano, Ryuichi Ohta, Takuma Aihara +3
We report an observation of phononic Schwinger angular momenta, which fully represent twomode states in a micromechanical resonator. This observation is based on simultaneous optic…
Strain-induced exciton decomposition and anisotropic lifetime modulation in a GaAs micromechanical resonator
Ryuichi Ohta, Hajime Okamoto, Takehiko Tawara +2
We demonstrate mechanical modulations of the exciton lifetime by using vibrational strain of a gallium arsenide (GaAs) resonator. The strain-induced modulations have anisotropic de…
Limit cycles and bifurcations in a nonlinear MEMS oscillator with a 1:3 internal resonance. Part I: The case of a driven resonator
S. Houri, D. Hatanaka, M. Asano +2
This work investigates the behavior of an AlGaAs/GaAs piezoelectric nonlinear MEMS oscillator exhibiting a 1:3 internal resonance. The device is explored in an open-loop configurat…
Pulse-width modulated oscillations in a nonlinear resonator under two-tone driving as a means for MEMS sensor readout
Samer Houri, Ryuichi Ohta, Motoki Asano +2
A MEMS Duffing resonator is driven by two adjacent frequency tones into the nonlinear regime. We show that if the two-tone drive is applied at a frequency where a bistable response…
An opto-electro-mechanical system based on evanescently-coupled optical microbottle and electromechanical resonator
Motoki Asano, Ryuichi Ohta, Takashi Yamamoto +2
Evanescent coupling between a silica optical microbottle resonator and a GaAs electromechanical resonator is demonstrated. This coupling provides high optical sensitivity and effic…
Coherent coupling of dark and bright excitons with vibrational strain
Ryuichi Ohta, Hajime Okamoto, Takehiko Tawara +2
In many physical systems, there are specific electronic states called dark state that are protected from the rapid radiative decay imposed by the system symmetry. Although their lo…
Vacuum Rabi spectra of a single quantum emitter
Yasutomo Ota, Ryuichi Ohta, Naoto Kumagai +2
We report the observation of the vacuum Rabi splitting of a single quantum emitter by measuring its direct spontaneous emission into free space. We used a semiconductor quantum dot…
Ultralow mode-volume photonic crystal nanobeam cavities for high efficiency coupling to individual carbon nanotube emitters
R. Miura, S. Imamura, R. Ohta +6
We report on high efficency coupling of individual air-suspended carbon nanotubes to silicon photonic crystal nanobeam cavities. Photoluminescence images of dielectric- and air-mod…