160 citations · 440 across the 19 of their papers we have counts for
19 papers
Control of emission interval and timing in triggered periodic superradiance
Hideaki Hara, Riku Omoto, Noboru Sasao +6
To achieve more controllable development of coherence in solids, we investigated the effect of a trigger laser tuned to the superradiance transition wavelength on periodic superrad…
Analytical and numerical studies of periodic superradiance
Hideaki Hara, Yuki Miyamoto, Junseok Han +6
We conduct a theoretical study to understand the periodic superradiance observed in an Er:YSO crystal. First, we construct a model based on the Maxwell-Bloch equations for a reduce…
Measurement of cesium electric quadrupole transition probabilities using fluorescence spectroscopy
Jing Wang, Yuki Miyamoto, Hideaki Hara +3
Fluorescence spectra of the ( and = 3/2, 1/2) electric quadrupole transition of cesium atoms have been observed with a heated cesium vapor cell…
Periodic super-radiance in Er:YSO crystal
Hideaki Hara, Junseok Han, Yasutaka Imai +5
We observed periodic optical pulses from an Er:YSO crystal during irradiating with an continuous-wave excitation laser. We refer to this new phenomenon as "periodic super-radiance"…
Parity violating magnetization at neutrino pair emission using trivalent lanthanoid ions
H. Hara, A. Yoshimi, M. Yoshimura
A new detection method using magnetization generated at triggered radiative emission of neutrino pairs (RENP), (ato…
Divalent lanthanoid ions in crystals for neutrino mass spectroscopy
H. Hara, N. Sasao, M. Yoshimura
Electron spin flip in atoms or ions can cause neutrino pair emission, which provides a method to explore still unknown important neutrino properties by measuring spectrum of emitte…
Raman stimulated neutrino pair emission
H. Hara, M. Yoshimura
A new scheme using macroscopic coherence is proposed from a theoretical point to experimentally determine the neutrino mass matrix, in particular the absolute value of neutrino mas…
X-ray pumping of the Th-229 nuclear clock isomer
Takahiko Masuda, Akihiro Yoshimi, Akira Fujieda +27
Thorium-229 is a unique case in nuclear physics: it presents a metastable first excited state Th-229m, just a few electronvolts above the nuclear ground state. This so-called isome…
Geometry-dependent spectra and coherent-transient measurement of nearly degenerate four-wave mixing using two-photon resonance
Hideaki Hara, Yuki Miyamoto, Takahiro Hiraki +7
We study nearly degenerate four-wave mixing using a two-photon-allowed vibrational transition of parahydrogen. A signal photon is generated by a trigger photon and coherence among…
Coherent two-photon emission from hydrogen molecules excited by counter-propagating laser pulses
Takahiro Hiraki, Hideaki Hara, Yuki Miyamoto +7
We observed two-photon emission signals from the first vibrationally excited state of parahydrogen gas excited coherently by counter-propagating laser pulses. A single narrow-linew…
Nuclear resonant scattering experiment with fast time response: new scheme for observation of Th radiative decay
A. Yoshimi, H. Hara, T. Hiraki +24
Nuclear resonant excitation of the 29.19-keV level in Th with high-brilliance synchrotron- radiation and detection of its decay signal, are proposed with the aim of populat…
Fast X-ray detector system with simultaneous measurement of timing and energy for a single photon
T. Masuda, S. Okubo, H. Hara +12
We developed a fast X-ray detector system for nuclear resonant scattering (NRS) experiments. Our system employs silicon avalanche photo-diode (Si-APD) as a fast X-ray sensor. The s…
Vibrational two-photon emission from coherently excited solid parahydrogen
Yuki Miyamoto, Hideaki Hara, Takahiko Masuda +5
We report observation of two-photon emission from coherently excited vibrational state of solid parahydrogen, known as one of quantum solids. The coherent state between the ground…
Injection seeded tunable mid-infrared pulses by difference frequency mixing
Yuki Miyamoto, Hideaki Hara, Takahiko Masuda +3
We report on the generation of nanosecond mid-infrared pulses having frequency tunability, a narrow linewidth, and a high pulse energy. These pulses are obtained by frequency mixin…
Externally triggered coherent two-photon emission from hydrogen molecules
Yuki Miyamoto, Hideaki Hara, Takahiko Masuda +6
We report coherent enhancement of two-photon emission from the excited vibrational state of molecular hydrogen triggered by irradiating mid-infrared pulses externally. We previousl…
Observation of coherent two-photon emission from the first vibrationally-excited state of hydrogen molecules
Yuki Miyamoto, Hideaki Hara, Susumu Kuma +10
In this paper, we describe an experiment which was conducted to explore the macro-coherent amplification mechanism using a two-photon emission process from the first vibrationally-…
A Three-Dimensional Optical Lattice of Ytterbium and Lithium Atomic Mixture
Hideaki Hara, Hideki Konishi, Shuta Nakajima +2
We develop an optical lattice system for an ultracold atomic gas mixture of ytterbium (174Yb) and lithium (6Li), which is an ideal system to study disorder and impurity problems. W…
Quantum degenerate mixtures of alkali and alkaline-earth-like atoms
Hideaki Hara, Yosuke Takasu, Yoshifumi Yamaoka +2
We realize simultaneous quantum degeneracy in mixtures consisting of the alkali and alkalineearth-like atoms Li and Yb. This is accomplished within an optical trap by sympathetic c…
Simultaneous magneto-optical trapping of lithium and ytterbium atoms towards production of ultracold polar molecules
M. Okano, H. Hara, M. Muramatsu +4
We have successfully implemented the first simultaneous magneto-optical trapping (MOT) of lithium (Li) and ytterbium (Yb) atoms, towards production of ultracold polar m…