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

29pTA-14 Dynamics of two-component Bose-Einstein condensates in an optical trap

Hamazaki K, Iwata M, Kuwamoto T, Hirano T

Meeting abstracts of the Physical Society of Japan, 61(1) 174-174, Mar 4, 2006
30pSA-8 Pulse-mode homodyne detection of squeezed light at telecommunication wavelength

Eto Y, Tajima T, Hirano T

Meeting abstracts of the Physical Society of Japan, 61(1) 188-188, Mar 4, 2006
30aSA-9 Free space continuous variable quantum cryptography

Tokunaga S, Shirasaki K, Hirano T

Meeting abstracts of the Physical Society of Japan, 61(1) 179-179, Mar 4, 2006
29pTA-13 Topological Vortex Nucleation in Bose-Einstein Condensates

Usuda Hayato, Nara Yuki, Kuwamoto Takeshi, Hirano Takuya

Meeting abstracts of the Physical Society of Japan, 61(1) 173-173, Mar 4, 2006
真空雑音を制御する：直交スクイーズド光の発生と検出

平野琢也

月刊オプトロニクス, 25(298) 168-175, 2006
量子限界の克服：光のスクイーズド状態

平野琢也

月刊オプトロニクス, 25(297) 165-170, 2006
Practical implementation,of continuous-variable quantum key distribution

Takuya Hirano, Atsushi Shimoguchi, Kazuya Shirasaki, Shingo Tokunaga, Atsushi Furuki, Yohei Kawamoto, Ryo namiki

QUANTUM INFORMATION AND COMPUTATION IV, 6244, 2006
19aWA-6 Collective Excitation of Bose-Einstein Condensates Induced by Rf Evapolative Colling

Kuwamoto T, Hamazaki K, Usuda H, Kikuchi M, Iwata M, Nara Y, Hirano T

Meeting abstracts of the Physical Society of Japan, 60(2) 44-44, Aug 19, 2005
21pWA-10 Free space continuous variable quantum cryptography using a single pass interferometer

Shirasaki K, Tokunaga S, Himeno T, Hirano T

Meeting abstracts of the Physical Society of Japan, 60(2) 77-77, Aug 19, 2005
21pWA-11 Generation of pulsed entanglement of continuous variables

Furuta T, Takahashi K, Hirano T

Meeting abstracts of the Physical Society of Japan, 60(2) 77-77, Aug 19, 2005
Security of continuous-variable quantum cryptography using coherent states: Decline of postselection advantage

R Namiki, T Hirano

PHYSICAL REVIEW A, 72(2), Aug, 2005
Security of continuous-variable quantum cryptography using coherent states: Decline of postselection advantage

R Namiki, T Hirano

PHYSICAL REVIEW A, 72(2) 024301, Aug, 2005
3 dB squeezing by single-pass parametric amplification in a periodically poled KTiOPO4 crystal

T Hirano, K Kotani, T Ishibashi, S Okude, T Kuwamoto

OPTICS LETTERS, 30(13) 1722-1724, Jul, 2005
3 dB squeezing by single-pass parametric amplification in a periodically poled KTiOPO4 crystal

T Hirano, K Kotani, T Ishibashi, S Okude, T Kuwamoto

OPTICS LETTERS, 30(13) 1722-1724, Jul, 2005
量子テレポーテーション (特集非古典的な光が導く量子情報処理の世界)

平野琢也

O plus E, 27(6) 655-659, Jun, 2005
27pYE-11 Experimental demonstration of "Plug and Play" quantum cryptography with continuous variables

Shimoguchi Atsushi, Kawamoto Yohei, Ashikaga Masanori, Ohta Keisuke, Hirano Takuya

Meeting abstracts of the Physical Society of Japan, 60(1) 187-187, Mar 4, 2005
27pYE-12 Generation of squeezed light at telecommunication wavelength

Eto Y, Tajima T, Hirano T

Meeting abstracts of the Physical Society of Japan, 60(1) 187-187, Mar 4, 2005
量子テレポーテーション

O plus E, 特集「非古典的な光が導く量子情報処理の世界」, vol.27, No. 6, pp. 655-659, 2005
12pTF-10 Magnetic field dependence of the dynamics of spin-2 spinor Bose-Einstein condensates

Kuwamoto T, Eno T, Hirano T

Meeting abstracts of the Physical Society of Japan, 59(2) 98-98, Aug 25, 2004
14pTF-1 Generation of squeezed light using a periodically poled LiNbO_3 waveguide

Furuta T, Ishibashi T, Hirano T

Meeting abstracts of the Physical Society of Japan, 59(2) 124-124, Aug 25, 2004
15aTF-12 Security of practical continuous-variable quantum cryptography using coherent states based on postselection

Namiki Ryo, Hirano Takuya

Meeting abstracts of the Physical Society of Japan, 59(2) 132-132, Aug 25, 2004
Quantum Communication and Key Distribution from a View Point of Optical Technology

NAMIKI Ryo, HIRANO Takuya

Japanese journal of optics, 33(8) 448-453, Aug 10, 2004
Magnetic field dependence of the dynamics of Rb-87 spin-2 Bose-Einstein condensates

T Kuwamoto, K Araki, T Eno, T Hirano

PHYSICAL REVIEW A, 69(6), Jun, 2004
Magnetic field dependence of the dynamics of Rb-87 spin-2 Bose-Einstein condensates

T Kuwamoto, K Araki, T Eno, T Hirano

PHYSICAL REVIEW A, 69(6) 063604, Jun, 2004
Quantum Optics and Nonlinear Optics

HIRANO Takuya

光学, 33(4) 213-214, Apr 10, 2004
Practical limitation for continuous-variable quantum cryptography using coherent states

R Namiki, T Hirano

PHYSICAL REVIEW LETTERS, 92(11), Mar, 2004
光学から見た量子通信・鍵配布

光学, vol. 33, no.8, p.448-453, 2004
Practical Limitation for Continuous-Variable Quantum Cryptography using Coherent States

R. Namiki, T. Hirano

Phys. Rev. Lett., 92(11) 117901, 2004
Quantum cryptography using pulsed homodyne detection

T Hirano, H Yamanaka, M Ashikaga, Konishi, I, R Namiki

PHYSICAL REVIEW A, 68(4), Oct, 2003
Quantum cryptography using pulsed homodyne detection

T Hirano, H Yamanaka, M Ashikaga, Konishi, I, R Namiki

PHYSICAL REVIEW A, 68(4) 042331, Oct, 2003
Quantum key distribution with a single photon from a squeezed coherent state

M Matsuoka, T Hirano

PHYSICAL REVIEW A, 67(4), Apr, 2003
Quantum key distribution with a single photon from a squeezed coherent state

M Matsuoka, T Hirano

PHYSICAL REVIEW A, 67(4) 042307, Apr, 2003
Optical Trapping of F=1 and F=2 Bose-Einstein Condensates

Araki K, Kikuchi N, Eno T, Kuwamoto T, Hirano T

Meeting abstracts of the Physical Society of Japan, 58(1) 143-143, Mar 6, 2003
The motion of Bose-Einstein Condensate in an optical trap

Kikuchi N, Araki K, Eno T, Kuwamoto T, Hirano T

Meeting abstracts of the Physical Society of Japan, 58(1) 143-143, Mar 6, 2003
Manipulation of Spin States of F=2,^<87>Rb BEC in an Optical Trap

Kuwamoto T, Araki K, Eno T, Kikuchi N, Hirano T

Meeting abstracts of the Physical Society of Japan, 58(1) 144-144, Mar 6, 2003
Experimental quantum communication using pulsed light

HIRANO Takuya

應用物理, vol. 72, no.2, p.163-168(2) 163-168, Feb 10, 2003
Security of quantum cryptography using balanced homodyne detection

R Namiki, T Hirano

PHYSICAL REVIEW A, 67(2), Feb, 2003
Security of quantum cryptography using balanced homodyne detection

R Namiki, T Hirano

PHYSICAL REVIEW A, 67(2) 022308, Feb, 2003
Optical dipole trap force of Bose-Einstein Condensate II

Araki K, Eno T, Kikuchi N, Kuwamoto T, Hirano T

Meeting abstracts of the Physical Society of Japan, 57(2) 120-120, Aug 13, 2002
Generation of squeezed light using a periodically poled KTP crystal.

Okude S, Kotani K, Ishibashi T, Hirano T

Meeting abstracts of the Physical Society of Japan, 57(2) 138-138, Aug 13, 2002
Present status of the quantum cryptography experiment using balanced homodyne detection in Gakushuin University

Yamanaka H, Namiki R, Ichikawa T, Ashikaga M, Hirano T

Meeting abstracts of the Physical Society of Japan, 57(2) 138-138, Aug 13, 2002
Single-photon-slate generation by squeezing of coherent state

MATSUOKA Masahiro, HIRANO Takuya

Meeting abstracts of the Physical Society of Japan, 57(2) 139-139, Aug 13, 2002
Security of quantum cryptography using balanced homodyne detection against beamsplitting attack

Namiki R, Hirano T

Meeting abstracts of the Physical Society of Japan, 57(2) 139-139, Aug 13, 2002
Quantum cryptography Basic concepts and technological issues

Hirano Takuya

IEICE technical report. Electron devices, 101(721) 27-32, Mar 8, 2002

Basic concepts and technological issues of quantum cryptography are reviewed.
24pWM-7 Single-photon-state generation by squeezing of coherent stale

MATSUOKA Masahiro, HIRANO Takuya

Meeting abstracts of the Physical Society of Japan, 57(1) 118-118, Mar 1, 2002
27pWM-10 Dispersive imaging of a Bose-Einstein condensate

Kondo K, Yoshikawa Y, Araki K, Kuwamoto T, Hirano T

Meeting abstracts of the Physical Society of Japan, 57(1) 169-169, Mar 1, 2002
27pWM-11 Collectiv Excitations of a Bose-Einstein CondensateInduced by Off-Resonant Light Beam

Yoshikawa Y, Kondo K, Araki K, Kuwamoto T, Hirano T

Meeting abstracts of the Physical Society of Japan, 57(1) 170-170, Mar 1, 2002
Higher transmission rate Quantum cryptography using balanced homodyne detection

K. Kaori, Namiki R, Yamanaka H, Fujii J, Hirano T

Meeting abstracts of the Physical Society of Japan, 56(2) 61-61, Sep 3, 2001
The wigner distributions on quantum cryptography using balanced homodyne detection and eavesdropping

Namiki R, Yamanaka H, Kotani K, Fujii J, Hirano T

Meeting abstracts of the Physical Society of Japan, 56(2) 62-62, Sep 3, 2001
Development of a narrow band high power laser system using a Broad-area diode laser

Sasaki Y, Ito K, Yosikawa Y, Kondo K, Torii Y, Kuwamoto T, Hirano T

Meeting abstracts of the Physical Society of Japan, 56(1) 93-93, Mar 9, 2001

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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