Dispersive measurement of spin shot noise in a Bose-Einstein condensate

Kosuke Shibata, Naota Sekiguchi, Junnosuke Takai, Takuya Hirano

Physical Review Research, Oct 14, 2025
Multistate interferometric measurement of the nonlinear ac Stark shift

Junnosuke Takai, Kosuke Shibata, Naota Sekiguchi, Takuya Hirano

Physical Review A, May 11, 2023
Highly efficient measurement of optical quadrature squeezing using a spatial light modulator controlled by machine learning

Jorge Amari, Junnosuke Takai, Takuya Hirano

Optics Continuum, Apr 15, 2023
Improved waveguide-based ultraviolet light generation and pulsed squeezing at 795 nm

Aki Torii, Kosuke Shibata, Yujiro Eto, Takuya Hirano

Optics Express, 30(15) 26120-26120, Jul 18, 2022 Peer-reviewed

We report on the waveguide-based generation of pulsed squeezed light at 795 nm, suitable for quantum enhanced measurements with rubidium atoms. Pulsed ultraviolet second harmonic light with a power of more than 400 mW is produced using a periodically poled LiNbO₃ (PPLN) waveguide and is injected into another PPLN waveguide to generate quadrature squeezing. We find that the phase of the second harmonic pulse is shifted within a pulse, and we attribute the shift to heating due to blue-light induced infrared absorption (BLIIRA) from a comparison between the experiment and a numerical simulation. A squeezing level of −1.5(1) dB is observed in homodyne detection when we apply a linear phase shift to the local oscillator. The experiment and simulation imply that the squeezing level can be further improved by reducing BLIIRA.
Sensitive spatially resolved magnetometry using a Bose-condensed gas with a bright probe

Naota Sekiguchi, Kosuke Shibata, Aki Torii, Hiroyuki Toda, Ryohei Kuramoto, Daiki Fukuda, Takuya Hirano

Physical Review A, 104(4), Oct 28, 2021 Peer-reviewed

Misc.

240

光直交振幅変調による量子暗号通信

平野琢也, 並木亮, 中沢正隆, 吉田真人, 廣岡俊彦, 葛西恵介

応用物理学会春季学術講演会講演予稿集(CD-ROM), 64th, 2017
Multi-Level Ramsey Interferometry Using m_F=0 State in a Spin-2 Bose-Einstein Condensate

Nabeta Keita, Okada Ryotaro, Torii Aki, Sadgrove Mark, Shibayama Hitoshi, Eto Yujiro, Hirano Takuya

Meeting Abstracts of the Physical Society of Japan, 71 511-511, 2016

<p>我々は以前からスピン2ボース・アインシュタイン凝縮体のスピン制御技術を利用して、ラムゼイ干渉によりラーモア歳差運動の観測をしてきた。これまでは、初期状態が磁気副準位m_F_=2の状態で実験を行ってきたが、初期状態を適切に選ぶことで干渉計の感度を向上させることが予測されている。本発表ではm_F_=0を初期状態にした時のラジオ波によるスピンの回転とラムゼイ干渉について報告する。</p>
Non-equilibrium dynamics induced by miscibility control in binary Bose-Einstein condensates

Eto Yujiro, Takahashi Masahiro, Kunimi Masaya, Saito Hiroki, Hirano Takuya

Meeting Abstracts of the Physical Society of Japan, 71 505-505, 2016

<p>多成分流体の空間的な構造形成は、非平衡過程や非線型現象を理解する上で重要な効果である。我々は、2成分ボース・アインシュタイン凝縮体の混和性を制御することにより、不安定な空間構造を持つ混ざり合う性質の2成分凝縮体を生成し、パターン形成ダイナミクスを観測することに成功した。発表では、混和性制御の方法や実験結果の詳細について紹介する。</p>
21pBJ-4 Real-time key generation using high-speed continuous variable Quantum key distribution system 2

Matsubara T, Ono M, Ichikawa T, Hirano T, Kasai K, Matsumoto R, Tsurumaru T

Meeting Abstracts of the Physical Society of Japan, 71 746-746, 2016
19aBK-10 Rabi Oscillation between Zeeman States in ^<87>Rb Bose-Einstein Condensate

Okada R, Nabeta K, Torii A, Takahashi M, Eto Y, Kunimi M, Saito H, Hirano T

Meeting Abstracts of the Physical Society of Japan, 71 632-632, 2016
20pBR-7 Flow and current in muti-component cold atomic gases

Eto Y, Takahashi M, Hirano T, Kunimi M, Saito H

Meeting Abstracts of the Physical Society of Japan, 71 1680-1681, 2016
17pAC-8 Generation of physical random numbers by using homodyne detection

Hirakawa K, Oguri Y, Kono K, Oya S, Nakano T, Ichikawa T, Hirano T, Tsurumaru T

日本物理学会講演概要集, 70(2) 528-528, Sep 16, 2015
17pAC-9 Observation of entangled light pulses using shaped local oscillator II

Shinjo A, Kikuchi S, Eto Y, Hirano T

日本物理学会講演概要集, 70(2) 529-529, Sep 16, 2015
18aBA-5 Collision and oscillation damping in multicomponent Bose-Einstein condensates

Eto Y, Takahashi M, Okada R, Nabeta K, Kunimi M, Saito H, Hirano T

日本物理学会講演概要集, 70(2) 550-550, Sep 16, 2015
Spin Texture Formation Induced by Weak Magnetic Dipole Interaction in a Bose-Einstein Condensate : Magnetic Gas of Ultracold Rb Atoms(Research)

Eto Yujiro, Saito Hiroki, Hirano Takuya

日本物理學會誌, 70(8) 614-619, Aug 5, 2015

We observed the spin texture formation and the spatial modulation of the longitudinal magnetization in a spin-2 ^<87>Rb Bose-Einstein condensate. The observed results are compared with numerical simulations of the Gross-Pitaevskii equation, which are the effects due to the magnetic dipole-dipole interaction. These results show that the magnetic dipole-dipole interaction has significant effects even on spinor condensates of alkali metal atoms.
22pAG-4 Stability of the spin domain in two-component Bose-Einstein condensates

Tokita H, Kunimi M, Okada R, Nabeta K, Eto Y, Saito H, Hirano T

日本物理学会講演概要集, 70(1) 665-665, Mar 21, 2015
23pAN-3 Observation of entangled light pulses using shaped local oscillator

Hashiyama N, Shinjo A, Kobayashi S, Eto Y, Hirano T

日本物理学会講演概要集, 70(1) 713-713, Mar 21, 2015
23pAN-4 Parametric amplification using a type-ll PPKTP waveguide

Kihara S, Matsui T, Eto Y, Hirano T

日本物理学会講演概要集, 70(1) 714-714, Mar 21, 2015
23pAN-5 Real-time key generation using high-speed Continuous Variable Quantum Key Distribution system

Oguri Y, Ishii V, Matsubara T, Ichikawa T, Hirano T, Kasai K, Tsurumaru T, Matsumoto R

日本物理学会講演概要集, 70(1) 715-715, Mar 21, 2015
9aAW-5 Dipolar-Induced Spin Texture in a Rb Bose-Einstein Condensate

Eto Yujiro, Saito Hiroki, Hirano Takuya

Meeting abstracts of the Physical Society of Japan, 69(2) 80-80, Aug 22, 2014
27pCC-6 Generation of pulsed squeezed light at telecommunication wavelength using a high efficiency PPLN optical waveguide

Togawa Shota, Nakagawa Hiroki, Eto Yujiro, Hirano Takuya, Utsugida Takuya, Kurimura Sunao, Nakajima Hirochika

Meeting abstracts of the Physical Society of Japan, 69(1) 177-177, Mar 5, 2014
28pCF-5 Noise performance of the polarimeter using CCD camera

Tomiyama Y, Hasegawa S, Tokita H, Eto Y, Hirano T

Meeting abstracts of the Physical Society of Japan, 69(1) 194-194, Mar 5, 2014
28pCF-6 Observation of Larmor precession of ^<87>Rb spin-2 BEC 4

Hasegawa S, Tomiyama Y, Iwade S, Tokita H, Eto Y, Saito H, Hirano T

Meeting abstracts of the Physical Society of Japan, 69(1) 194-194, Mar 5, 2014
30pCC-1 Implementation and Reduction of Excess Noise in "Plug & Play" Continuous-Variable Quantum Key Distribution

Miyazaki J, Ichikawa T, Hirano T

Meeting abstracts of the Physical Society of Japan, 69(1) 225-225, Mar 5, 2014
30pCC-2 Continuous-Variable Quantum Key Distribution using a single-path interferometer VII

Koike Y, Ishii V, Oguri Y, Ichikawa T, Hirano T, Kasai K, Matsumoto R, Tsurumaru T

Meeting abstracts of the Physical Society of Japan, 69(1) 225-225, Mar 5, 2014
30pCC-3 Security analysis of continuous variable quantum key distribution with detector noise and transmittance

Ichikawa Tsubasa, Hirano Takuya

Meeting abstracts of the Physical Society of Japan, 69(1) 225-225, Mar 5, 2014
Magnetometer using Bose-Einstein condensates

ETO Yujiro, HIRANO Takuya

應用物理, 82(9) 769-772, Sep 10, 2013
Larmor precession of spin-2 Bose-Einstein condensates subject to a magnetic field gradient

Eto Y, Hasegawa S, Tomiyama Y, Tokita H, Iwade S, Sadgrove M, Saito H, Hirano T

Meeting abstracts of the Physical Society of Japan, 68(2) 144-144, Aug 26, 2013
The Nobel Prize in Physics 2012 : Progress in Cavity Quantum Electrodynamics

HIRANO Takuya

レーザー研究, 41(7) 474-478, Jul 15, 2013
26aED-7 High speed operation of Continuous Variable Quantum Key Distribution

Oguri Y, Sato S, Hata M, Koike Y, Miyazaki J, Ichikawa T, Hirano T

Meeting abstracts of the Physical Society of Japan, 68(1) 184-184, Mar 26, 2013
26aED-8 Continuous-Variable Quantum Key Distribution using a single-path interferometer VI

Koike Y, Ichikawa T, Hirano T

Meeting abstracts of the Physical Society of Japan, 68(1) 185-185, Mar 26, 2013
26aED-9 On conditional squashing model and quadrature amplitude measurements

Ichikawa Tsubasa, Tsurumaru Toyohiro, Hirano Takuya

Meeting abstracts of the Physical Society of Japan, 68(1) 185-185, Mar 26, 2013
27aEE-13 Observation of Larmor precession of spin-2 BEC 3

Sekine S, Tomiyama Y, Hasegawa S, Ikeda H, Suzuki H, Sadgrove Mark, Eto Y, Hirano T

Meeting abstracts of the Physical Society of Japan, 68(1) 213-213, Mar 26, 2013
27aEE-14 Magnetometer with spinor Bose-Einstein condensates

Eto Y, Sekine S, Tomiyama Y, Hasegawa S, Ikeda H, Suzuki H, Hirano T

Meeting abstracts of the Physical Society of Japan, 68(1) 213-213, Mar 26, 2013
黒体輻射 (特集光と物理学)

平野琢也

数理科学, 51(3) 36-41, Mar, 2013
On the Key Rate of Continuous Variable Quantum Key Distribution with Discrete Modulations under Entangling Cloner Attacks

市川翼, 村山和裕, 平野琢也

量子情報技術研究会資料, 27 182-185, Nov 27, 2012
18pAK-1 On the Key Hate of Continuous Variable Quantum Key Distribution with Discrete Modulations under Entangling Cloner Attacks

Ichikawa Tsubasa, Murayama Kazuhiro, Hirano Takuya

Meeting abstracts of the Physical Society of Japan, 67(2) 131-131, Aug 24, 2012
18pAK-2 Continuous-Variable Quantum Key Distribution using a single-path interferometer V

Koike Y, Murayama K, Ichikawa T, Hirano T

Meeting abstracts of the Physical Society of Japan, 67(2) 131-131, Aug 24, 2012
18pAK-3 Reduction of excess noise in "plug & play" implementations of continuous-variable quantum key distribution

Miyazaki Jun, Hirano Takuya

Meeting abstracts of the Physical Society of Japan, 67(2) 131-131, Aug 24, 2012
19pAL-4 Mixing dynamics of the Countersuperflow between binary Bose-Einstein condensates II

Masuyama Y, Sadgrove Mark, Hirano T

Meeting abstracts of the Physical Society of Japan, 67(2) 156-156, Aug 24, 2012
19pAL-7 Observation of Larmor precession of ^<87>Rb spin-2 BEC 2

Sekine S, Tomiyama Y, Hasegawa S, Ikeda H, Suzuki H, Sadgrove Mark, Eto Y, Hirano T

Meeting abstracts of the Physical Society of Japan, 67(2) 156-156, Aug 24, 2012
G. Grynberg, A. Aspect and C. Fabre, Introduction to Quantum Optics; From the Semi-classical Approach to Quantized Light, Cambridge Univ. Press, New York, 2010, xxix+665p, 26×20 cm, £45.00, [大学院・学部向], ISBN 978-0-521-55112-0

平野琢也

日本物理學會誌, 67(8) 592-592, Aug 5, 2012
Clouds of atoms with opposite spins bounce off one another

レヴィバーバラ・ゴス, 平野琢也

パリティ, 27(5) 30-32, May, 2012
Atoms in a BEC engineered to have spin-orbit coupling typical of electrons in a solid

レヴィバーバラ・ゴス, 平野琢也

パリティ, 27(4) 34-37, Apr, 2012
24pBE-6 Continuous-Variable Quantum Key Distribution using a single-path interferometer IV

Murayama K, Koike Y, Hirano T

Meeting abstracts of the Physical Society of Japan, 67(1) 193-193, Mar 5, 2012
27aSA-5 Observation of Larmor precession of ^<87>Rb spin-2 BEC

Sadgrove Mark, Sekine S, Masuyama Y, Ota K, Tomiyama Y, Hasegawa S, Tojo S, Hirano T

Meeting abstracts of the Physical Society of Japan, 67(1) 234-234, Mar 5, 2012
27aSA-6 Mixing dynamics of the Countersuperflow between binary Bose-Einstein condensates

Masuyama Y, Sadgrove Mark, Sekine S, Ota K, Tomiyama Y, Hasegawa S, Tojo S, Hirano T

Meeting abstracts of the Physical Society of Japan, 67(1) 234-234, Mar 5, 2012
領域1・領域4「多様な物理系の量子制御と量子情報処理の科学」(2011年秋季大会シンポジウムの報告,学会報告)

平野琢也

日本物理學會誌, 67(2) 115-115, Feb 5, 2012
現代に至るまでの量子力学 (特集古典のススメ(物理編))

平野琢也

数理科学, 50(2) 55-60, Feb, 2012
21pED-8 Continuous-Variable Quantum Key Distribution using a single-path interferometer III

Murayama K, Kawasoe R, Ido T, Koike Y, Hirano T

Meeting abstracts of the Physical Society of Japan, 66(2) 135-135, Aug 24, 2011
22pEC-1 Aim of the symposium

Hirano Takuya

Meeting abstracts of the Physical Society of Japan, 66(2) 154-154, Aug 24, 2011
23pED-9 Generation of pulsed squeezed light at telecommunication wavelength using a low loss waveguide

Nakamura K, Miuchi T, Tanaka S, Matsuda R, Hirano T

Meeting abstracts of the Physical Society of Japan, 66(2) 175-175, Aug 24, 2011
23pED-10 Generation of Squeezed Light Using cw Mode-Locked Laser and Waveguide

Eto Y, Sakurai J, Horie K, Koshio A, Ohshiro A, Sasaki M, Hirano T

Meeting abstracts of the Physical Society of Japan, 66(2) 175-175, Aug 24, 2011
24pEE-7 Observation of ^<87>Rb spin-2 BEC using the phase contrast imaging

Sekine S, Masuyama Y, Sadgrove Mark, Tojo S, Hirano T

Meeting abstracts of the Physical Society of Japan, 66(2) 194-194, Aug 24, 2011
24pEE-8 Mixing dynamics of binary ^<87>Rb Bose-Einstein condensates in an optical trap 2

Masuyama Y, Taguchi Y, Sekine S, Sadgrove Mark, Tojo S, Hirano T

Meeting abstracts of the Physical Society of Japan, 66(2) 194-194, Aug 24, 2011

Books and Other Publications

Cold Atom Magnetometers, in Principles and Methods of Quantum Information Technologies

Yujiro Eto, Mark Sadrove, Takuya Hirano (Role: Joint author)

Springer Japan, 2016
光科学研究の最前線２分担執筆 I-1-2「非古典的光」

国際文献印刷社, 2009
基礎からの量子光学監修：(社)応用物理学会量子エレクトロニクス研究会, 松岡正浩、江馬一弘、平野琢也、岩本敏

オプトロニクス社, 2009 (ISBN: 9784902312423)
量子情報通信「コヒーレント光とホモダイン検波による量子鍵配送」,p.179-204

オプトロニクス社, 2006
物理学大事典，第１４章「量子光学」

朝倉書店, 2005

Professional Memberships

Works

Research Projects

空間位相変調器を用いた量子状態の高効率測定

科学研究費助成事業, 日本学術振興会, Apr, 2019 - Mar, 2023

平野琢也
Information communication technology ensuring the long term security over a century

Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Jun, 2018 - Mar, 2023
Broadcast continuous variable quantum key distribution

Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2018 - Mar, 2021

Takeoka Masahiro
Non-equilibrium Dynamics in Multi-component Bose-Einstein Condensates

Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Jun, 2013 - Mar, 2018

Hirano Takuya, TAKAHASHI Masahiro, ETO Yujiro, SHIBATA Kosuke
Synergy of Fluctuation and Structure : Quest for Universal Laws in Non-Equilibrium Systems

Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Jun, 2013 - Mar, 2018

SANO Masaki, SASA Shin-ichi, ORIHARA Hiroshi, IMAI Masayuki, KOMURA Shigeyuki, KIMURA Yasuyuki, HIRANO Takuya, ICHIKAWA Masatoshi, MIYAZAKI Kunimasa, YOSHIKAWA Kenichi, SAKURAI Tatsunari, KOBAYASHI Kensuke

Industrial Property Rights

特開2017-050678 光秘匿通信システム

中沢正隆, 吉田真人, 廣岡俊彦, 平野琢也
特許第5041256号量子エンタングルメント生成装置及び方法並びに量子エンタングルメント生成検出装置及び方法

平野琢也, 衛藤雄二郎
特許第4962700号量子暗号通信装置

川元洋平, 平野琢也, 篠邦宣, 浮田昌一
特許第4936157号量子暗号通信方法及び量子暗号通信装置

平野琢也
特許第4838166号量子暗号通信装置および通信端末

川元洋平, 平野琢也, 篠邦宣, 浮田昌一

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