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Nobuko Naka

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中 暢子
京都大学 大学院理学研究科 物理学・宇宙物理学専攻
物理学第一分野 准教授

略歴:静岡県生まれ。 東京大学理学部物理学科卒業、同大学院理学系研究科修士課程修了。 同大学院理学系研究科助手、理化学研究所基礎科学特別研究員、 東京大学大学院工学系研究科特任講師を経て2008年8月より現職。 2008年10月より2012年3月まで科学技術振興機構さきがけ研究員を兼務。 2013年8月より2015年7月まで文部科学省学術調査官を併任。

学位:博士(理学)(東京大学2003年) 「Two-photon spectroscopy on excitons in strain-induced traps in Cu2O」

 

専門分野:光物性物理学

所属学会:日本物理学会

連絡先

e-mail: naka@...(add scphys.kyoto-u.ac.jp after @)
居室:吉田キャンパス北部構内理学研究科5号館1階120号室

 

外部資金

科研費 基盤研究(B)(H29~R2) 光初期化したデルタバレー偏極の空間輸送制御 (代表)

科研費 挑戦的研究(萌芽)(R1~R2) 擬似定常白色コヒーレント光源を用いる革新的非線形分光法の開拓(代表)

 

Publications

  1. S. Hamabata, I. Akimoto, and N Naka: Temperature-dependent carrier injection routes under optical excitation in high-purity diamond crystals, J. Phys.: Conf. Ser. 1220 (2019) 012023-1-4.
  2. I. Akimoto and N. Naka: Intrinsic carrier parameters and optical carrier injection method in high-purity diamonds, IntechOpen (2019). DOI: 10.5772/intechopen.86002
  3. Y. Kubo, S. Temgoua, R. Issaoui, J. Barjon, and N. Naka: Radiative lifetime of boron-bound excitons in diamond, Appl. Phys. Lett. 114 (2019) 132104-1-4 (selected as an Editor's pick).
  4. Mitsuyoshi Takahata and Nobuko Naka: Photoluminescence properties of the entire excitonic series in Cu2O, Phys. Rev. B 98 (2018) 195205-1-10.
  5. Mitsuyoshi Takahata, Koichiro Tanaka, and Nobuko Naka: Superradiance-to-polariton crossover of Wannier excitons with multiple resonances, Phys. Rev. Lett. 121 (2018) 173604-1-6.
  6. T. Shimomura, Y. Kubo, J. Barjon, N. Tokuda, I. Akimoto, and N. Naka: Quantitative relevance of substitutional impurities to carrier dynamics in diamond, Phys. Rev. Mater. 2 (2018) 094601-1-7.
  7. Mitsuyoshi Takahata, Koichiro Tanaka, and Nobuko Naka: Nonlocal optical response of weakly confined excitons in Cu2O mesoscopic films, Phys. Rev. B 97 (2018) 205305-1-6.
  8. Florian Schoene, Heinrich Stolz, and Nobuko Naka: The phonon-assisted absorption of excitons in Cu2O, Phys. Rev. B 96 (2017) 115207-1-10.
  9. Tatsuya Kitamura, Mitsuyoshi Takahata, and Nobuko Naka: Quantum number dependence of the photoluminescence broadening of excitonic Rydberg states in cuprous oxide, J. Lumin. 192 (2017) 808–813.
  10. Ikuko Akimoto and Nobuko Naka: Two optical routes of cold carrier injection in silicon revealed by time-resolved excitation spectroscopy, Applied Physics Express 10 (2017) 061301-1-4 (selected for Spotlights). http://iopscience.iop.org/journal/1882-0786/page/Spotlights
  11. 中暢子、森本光、挾間優治、田中耕一郎: 高純度ダイヤモンドにおける励起子拡散のメカニズム(解説), 光アライアンス vol. 28, pp. 35 (2017年3月号). 
  12. Nobuko Naka, Hikaru Morimoto, and Ikuko Akimoto: Excitons and fundamental transport properties of diamond under photo-injection, Phys. Status Solidi A 213 (2016) 2551–2563 (Feature Article, selected for Front Cover).
  13. Hikaru Morimoto, Yuji Hazama, Koichiro Tanaka, and Nobuko Naka: Exciton lifetime and diffusion length in high-purity chemical-vapor-deposition diamond, Diamond Relat. Mater. 63 (2016) 47.
  14. I. Akimoto, N. Naka, and N. Tokuda: Time-resolved cyclotron resonance on dislocation-free HPHT diamond, Diamond Relat. Mater. 63 (2016) 38.
  15. Hikaru Morimoto, Yuji Hazama, Koichiro Tanaka, and Nobuko Naka, Ultrahigh exciton diffusion in intrinsic diamond, Phys. Rev. B 92 (2015) 201202(R)-1-5.
  16. Ikuko Akimoto, Katsuyuki Fukai, Yushi Handa, and Nobuko Naka: High carrier mobility in ultrapure diamond measured by time-resolved cyclotron resonance, App. Phys. Lett. 105 (2014) 032102-1-4.
  17. Yuji Hazama, Nobuko Naka, and Heinrich Stolz: Mass-anisotropy splitting of indirect excitons in diamond, Phys. Rev. B 90 (2014) 045209-1-7.
  18. Sandhaya Koirala, Mitsuyoshi Takahata, Yuji Hazama, Nobuko Naka, and Koichiro Tanaka: Relaxation of localized excitons by phonon emission at oxygen vacancies in Cu2O, J. Lumin. 155 (2014) 65-69.
  19. N. Naka, K. Fukai, Y. Handa, and I. Akimoto: Nanosecond cyclotron resonance in ultrapure diamond, J. Lumin. 152 (2014) 93-97.
  20. Yuji Hazama, Nobuko Naka, Makoto Kuwata-Gonokami, and Koichiro Tanaka: Resonant creation of indirect excitons in diamond at the phonon-assisted absorption edge, Europhys. Lett. 104 (2013) 47012-1-6.
  21. N. Naka, K. Fukai, Y. Handa, and I. Akimoto: Direct measurement via cyclotron resonance of the carrier effective masses in pristine diamond, Phys. Rev. B 88 (2013) 035205-1-5.
  22. J. Omachi, T. Suzuki, K. Kato, N. Naka, K. Yoshioka, and M. Kuwata-Gonokami: Observation of excitonic N-body bound states: polyexcitons in diamond, Phys. Rev. Lett. 111 (2013) 026402-1-5.
  23. N. Naka, I. Akimoto, and M. Shirai: Free-carrier generation by two-photon resonant excitation to the excitonic states in cuprous oxide, Phys. Status Solidi B 250 (2013) 1773-1776.
  24. Sandhaya Koirala, Nobuko Naka, and Koichiro Tanaka: Correlated lifetimes of paraexcitons and trapped excitons at oxygen vacancy in cuprous oxide, J. Lumin. 134 (2013) 524-527.
  25. Nobuko Naka and Junko Omachi: Trailing quantum phases in solids using light-matter interaction, Chapter 17 in "New Developments in Photon and Material Research" (NOVA Science Publishers, 2013) p.365-382.
  26. I. Akimoto, S. Torai, N. Naka, and M. Shirai: Temporal shift from magnetoplasma resonance to cyclotron resonance of photo-carriers generated from 1s-exciton in cuprous oxide crystal, Eur. Phys. J. B 85 (2012) 374-1-5.
  27. Heinrich Stolz, Rico Schwartz, Frank Kieseling, Sunipa Som, Maria Kaupsch, Siegfried Sobkowiak, and Dirk Semkat, Nobuko Naka, Thomas Koch, and Holger Fehske: Condensation of excitons in Cu2O at ultracold temperatures: experiment and theory, New J. Phys. 14 (2012) 105007-1-37.
  28. Rico Schwartz, Nobuko Naka, Frank Kieseling, and Heinrich Stolz: Dynamics of excitons in a potential trap at ultra-low temperatures: paraexcitons in Cu2O, New J. Phys. 14 (2012) 023054-1-28.
  29. Nobuko Naka, Ikuko Akimoto, Masanobu Shirai, and Ken-ich Kan'no: Time-resolved cyclotron resonance in Cu2O, Phys. Rev. B 85 (2012) 035209-1-6.
  30. T. Shikama, N. Naka, and M. Hasuo: Observation of the A2D-X2Pi transition spectra of CD molecules under a magnetic field relevant to fusion plasmas, Journal of Quantitative Spectroscopy and Radiative Transfer 113 (2012) 294-298.
  31. Christian Sandfort, Jan Brandt, Christoph Finke, Dietmar Froehlich, and Manfred Bayer, Heinrich Stolz and Nobuko Naka: Paraexcitons of Cu2O in a strain trap and high magnetic fields, Phys. Rev. B 84 (2011) 165215-1-7.
  32. N. Naka, J. Omachi, H. Sumiya, K. Tamasaku, T. Ishikawa, and M. Kuwata-Gonokami: Density-dependent exciton kinetics in synthetic diamond crystals, Phys. Rev. B 80 (2009) 035201-1-7.
  33. J. Omachi, N. Naka, K. Yoshioka, M. Kuwata-Gonokami: Formation control of electron-hole droplets in diamond by a weak pulse injection, Journal of Physics C: Conference Series 148 (2009) 012051-1-3.
  34. N. Naka, T. Kitamura, J. Omachi, and M. Kuwata-Gonokami: Generation of low-temperature excitons in diamond using a two-photon absorption process, Phys. Status Solidi B 245 (2008) 2676-2679.
  35. N. Naka, J. Omachi, and M. Kuwata-Gonokami: Suppressed formation of electron-hole droplets in diamond under a strain field, Phys. Rev. B 76 (2007) 193202-1-4.
  36. Jan Brandt, Dietmar Froehlich, Christian Sandfort, Manfred Bayer, Heinrich Stolz, and Nobuko Naka: Ultranarrow optical absorption and two-phonon excitation spectroscopy of Cu2O paraexcitons in a high magnetic field, Phys. Rev. Lett. 99 (2007) 217403-1-4.
  37. N. Naka and N. Nagasawa: Bosonic stimulation of cold excitons in a harmonic potential trap in Cu2O, J. Lumin. 112 (2005) 11-16.
  38. Nobuko Naka, Satoshi Hashimoto, and Teruya Ishihara: Thin films of single-crystal cuprous oxide grown from the melt, Jpn J. App. Phys. 44 (2005) 5096-5101.
  39. Naoya Tajima, Jun-ichi Fujisawa, Nobuko Naka, Teruya Ishihara, Reizo Kato, Yutaka Nishio, and Koji Kajita: Photo-induced insulator-metal transition in an organic conductor α-(BEDT-TTF)2I3, Journal of the Physical Society of Japan 74 (2005) 511-514.
  40. J.T. Ye, N. Naka, Y. Morihara, Z.K. Tang, W.K. Ge, P. Shen, I. Kudryashov, and N. Nagasawa: Optical micro-characterization of single-wall carbon nanotubes extracted from AFI crystals by visible emission and Raman scattering, Jpn J. App. Phys. 43 (2004) 7354-7355.
  41. N. Nagasawa, H. Sugiyama, N. Naka, I. Kudryashov, Z.M. Li, and Z.K. Tang: Optical nano-tomography on photosensitive single-wall carbon nanotube arrays in Zeolite (AFI) crystals, Jpn J. App. Phys. 43 (2004) 868-871.
  42. N. Naka and N. Nagasawa: Two-photon tomography of strain-induced potential wells of excitons in Cu2O, Phys. Rev. B 70 (2004) 155205-1-10.
  43. N. Naka and N. Nagasawa: Optical tracking of high-density cooled excitons in potential traps in Cu2O, Phys. Status Solidi B 238 (2003) 397-403.
  44. N. Naka and N. Nagasawa: Bosonic stimulation of cold 1s excitons into a harmonic potential minimum in Cu2O, Solid State Commun. 126 (2003) 523-525.
  45. Y. Kamada, N. Naka, S. Saito, N. Nagasawa, Z.M. Li, and Z.K. Tang: Photo-irradiation effects on electrical conduction of single wall carbon nanotubes in zeolite single crystals, Solid State Commun. 123 (2002) 375-378.
  46. N. Naka and N. Nagasawa: Nonlinear paraexciton kinetics in a potential trap in Cu2O under two-photon resonance excitation, Phys. Rev. B 65 (2002) 245203-1-5.
  47. Y. Kamada, N. Naka, N. Nagasawa, Z.M. Li, and Z.K. Tang: Photo-induced current-modulation in Zeolite crystals containing single wall carbon nanotubes, Physica B 323 (2002) 239-241.
  48. N. Nagasawa, H. Sugiyama, N. Naka, I. Kudryashov, M. Watanabe, T. Hayashi, I. Bozovic, N. Bozovic, G. Li, Z. Li, and Z.K. Tang: Visible emission of single-wall carbon nanotubes formed in micro-channels of Zeolite crystals, J. Lumin. 97 (2002) 161-167.
  49. N. Naka and N. Nagasawa: Two-photon diagnostics of stress-induced exciton traps and loading of 1s-yellow excitons in Cu2O, Phys. Rev. B 65 (2002) 075209-1-5.
  50. N. Naka and N. Nagasawa: Dynamics of paraexcitons generated in a 3D confined potential well by two-photon resonance excitation in Cu2O, J. Lumin. 94-95 (2001) 413-416.
  51. Y. Nakamura, N. Naka, and N. Nagasawa: Effects of wandering photons on the excitonic optical signals in Cu2O crystals, Phys. Rev. B 64 (2001) 075203-1-6.
  52. A. Mori, N. Naka, and N. Nagasawa: Effects of Rayleigh scattering on photovoltaic spectra associated with 1s orthoexcitons in Cu2O, Phys. Rev. B 63 (2001) 033202-1-4, ibid 169901(E)-1.
  53. N. Naka and N. Nagasawa: Two-photon spectroscopy on cold ortho-excitons in a stress trap in Cu2O crystals, J. Lumin. 87-89 (2000) 201-203.
  54. N. Naka and N. Nagasawa: Experimental study on two-photon oscillator strength of hydrogenic yellow excitons in Cu2O, Solid State Commun. 116 (2000) 417-419.
  55. N. Naka and N. Nagasawa: High precision two-photon spectroscopy on emission of 1s ortho- excitons in Cu2O, Solid State Commun. 110 (1999) 153-157.
  56. N. Naka, M. Hasuo, and N. Nagasawa: Two-photon photo-voltaic spectroscopy on Wannier excitons in Cu2O, Physics of the Solid State 40 (1998) 847-849.
  57. S. Kono, N. Naka, M. Hasuo, S. Saito, T. Suemoto, and N. Nagasawa: Coherent optical processes of 1s ortho-excitons in Cu2O by two-photon excitation, Solid State Commun. 97 (1996) 445-458.
  58. N. Naka, S. Kono, M. Hasuo, and N. Nagasawa: A new aspect of the Bose-Einstein condensation of 1s-exciton system in Cu2O, Prog. in Crystal Growth and Charact. 33 (1996) 89-92.

Invited talks

  1. Nobuko Naka and Mitsuyoshi Takahata: Rydberg excitons in semiconductor Cu2O with bulk and mesoscopic dimensions, Fundamental Optical Processes in Semiconductors (FOPS) 2019, (Banff, Canada, August 2019).
  2. Nobuko Naka and Mitsuyoshi Takahata: Photoluminescence of Rydberg excitons in Cu2O, 3rd International Workshop on Rydberg Excitons in Semiconductors (Durham, UK, July 16, 2019).
  3. Nobuko Naka and Ikuko Akimoto: Optical injection of valley-polarized electrons in group IV semiconductors, EXCON2018 (Nara, Japan, July 13, 2018).
  4. Nobuko Naka, Hikaru Morimoto, and Ikuko Akimoto: Excitons and fundamental properties of diamond, Hasselt Diamond Workshop SBDD-XXI (Hasselt, Belgium, March 9, 2016).
  5. Nobuko Naka, Yuji Hazama, and Ikuko Akimoto: Excitons and carrier effective masses in intrinsic diamond, International Conference on Diamond and Carbon Materials (Madrid, Spain, September 10, 2014).
  6. Ikuko Akimoto and Nobuko Naka: Momentum relaxation times for optically excited delocalized electrons and holes in pristine diamond, Awaji International Workshop on “Electron Spin Science & Technology: Biological and Materials Science Oriented Applications” (Awaji, Japan, June 17, 2014).
  7. Nobuko Naka: Polyexcitons and electron-hole droplet condensation in diamond, 7th International Conference on Spontaneous Coherence in Excitonic Systems (Hakone, Japan, April 22, 2014).
  8. N. Naka: Strain confined excitons in Cu2O, 2nd International Conference on Spontaneous Coherence in Excitonic Systems (Southampton, UK, September 2005).
  9. N. Naka and N. Nagasawa: Bosonic stimulation of cold excitons in a harmonic potential trap in Cu2O, 6th International Conference on Excitonic Processes in Condensed Matter (Cracow, Poland, July 2004).
  10. N. Naka and N. Nagasawa: Optical tracking of high-density cooled excitons in potential traps in Cu2O, 7th International Workshop on Nonlinear Optics and Excitation Kinetics in Semiconductors (Karlsruhe, Germany, February 2003).
  11. N. Nagasawa, H. Sugiyama, N. Naka, I. Kudryashov, M. Watanabe, T. Hayashi, I. Bozovic, N. Bozovic, G. Li, Z. Li, and Z.K. Tang: Visible emission of single-wall carbon nanotubes formed in micro-channels of zeolite crystals, International Conference on Dynamical Processes in Excited States of Solids (Lyon, France, July 2001).
  12. N. Naka, M. Hasuo, and N. Nagasawa: Two-photon photo-voltaic spectroscopy on Wannier excitons in Cu2O, International Conference on Optics of Excitons in Condensed Matter, dedicated to the 100th anniversary of Professor E.F. Gross (St. Petersburg, Russia, September 1997).

Seminar and talks

  1. Y. Kubo, S. Temgoua, R. Issaoui, J. Barjon, and N. Naka: Radiative lifetime of boron-bound excitons in diamond studied by ultraviolet absorption, Hasselt Diamond Workshop SBDD-XXIV (Hasselt, Belgium, March 15, 2019).
  2. N. Naka, Excitonic luminescence in Cu2O with bulk and mesoscopic dimensions, (EIIa Seminar, Technical University of Dortmund, March 11, 2019).
  3. M. Takahata, K. Tanaka, and N. Naka: Excitonic response beyond the long-wavelength approximation in Cu2O mesoscopic films, EXCON2018 (Nara, Japan, July 9, 2018).
  4. N. Naka, S. Hamabata, K. Konishi, J.H. Kaneko, and I. Akimoto: Time-resolved spectroscopy on intrinsic diamond for reassessment of the exciton binding energy, Hasselt Diamond Workshop SBDD-XXIII (Hasselt, Belgium, March 7, 2018).
  5. N. Naka, I. Akimoto, T. Shimomura, Ian Friel, and J. Isberg: Enhanced electron mobility in intrinsic diamond at cryogenic temperatures, Hasselt Diamond Workshop SBDD-XXII (Hasselt, Belgium, March 10, 2017).
  6. Ikuko Akimoto and Nobuko Naka: Exciton interband relaxation observed by time-resolved cyclotron resonance in diamond, 19th International Conference on Dynamical Processes in Excited States of Solids (Paris, France, July 21, 2016).
  7. Nobuko Naka: Free-carrier mobility and exciton diffusion in diamond, GEMaC Seminar (Versailles, France, March 15, 2016).
  8. I. Akimoto, N. Naka, and N. Tokuda: Time-resolved cyclotron resonance on dislocation-free HPHT diamond, 9th international conference on new diamond and nano carbons 2015 (Shizuoka, Japan, May 26, 2015).
  9. I. Akimoto, Y. Handa, K. Fukai, and N. Naka: High carrier mobility of diamond measured by cyclotron resonance, The 15th IUMRS-International Conference in Asia (IUMRS-ICA 2014) (Fukuoka, Japan, August 26, 2014).
  10. Nobuko Naka and Ikuko Akimoto: High-efficiency detection of free carriers via Auger ionization in wide-gap semiconductors, 32nd international conference on the physics of semiconductors (Austin, Texas, August 14, 2014).
  11. Nobuko Naka, Katsuyuki Fukai, Yushi Handa, and Ikuko Akimoto: Nanosecond cyclotron resonance in ultrapure diamond, 18th International Conference on Dynamical Processes in Excited States of Solids (Fuzhou, China, August 6, 2013).
  12. Nobuko Naka: ナノ秒時間分解サイクロトロン共鳴:光物性研究への展開 (特別講義談話会,愛媛大学理学部,July 29, 2013).
  13. Yuji Hazama, Nobuko Naka, Makoto Kuwata-Gonokami, and Koichiro Tanaka: Influence of the carrier lifetime on the phase diagram of electron-hole systems in diamond, The 18th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Matsue, Japan, July 23, 2013).
  14. Nobuko Naka: The electron-hole liquid in diamond and cyclotron resonance in cuprous oxide, Vortrag in Rahmen des Optikseminars (Rostock, Germany, October 2, 2012).
  15. H. Stolz, R. Schwartz, F. Kieseling, S. Som, M. Kaupsch, S. Sobokowiak, D. Semkat, N. Naka, T. Koch, H. Fehske: Bose-Einstein condensation of excitons in Cu2O, 11th International Workshop on Nonlinear Optics and Excitation Kinetics in Semiconductors (Stuttgart, Germany, September 26, 2012).
  16. Nobuko Naka, Ikuko Akimoto, and Masanobu Shirai: Free-carrier generation by two-photon resonant excitation to the excitonic states in cuprous oxide, 11th International Workshop on Nonlinear Optics and Excitation Kinetics in Semiconductors (Stuttgart, Germany, September 24, 2012).
  17. Nobuko Naka: Low-temperature phases of electron-hole systems in diamond, DYCE International workshop (Kussharo, Japan, August 8, 2012).
  18. Nobuko Naka, Ikuko Akimoto, Shinji Torai, and Masanobu Shirai: Free-carrier generation by excitonic collisions studied by a time-resolved cyclotron resonance in cuprous oxide, 31st International conference on the physics of semiconductors (Zurich, Switzerland, July 30, 2012).
  19. Yuji Hazama, Nobuko Naka, Makoto Kuwata-Gonokami, and Koichiro Tanaka: Lifetime effect on the electron-hole-droplet formation in diamond, 10th International Conference on Excitonic Processes in Condensed Matter, Nanostructured and Molecular Materials (Groningen, Netherlands, July 2, 2012).
  20. Nobuko Naka, Ikuko Akimoto, and Masanobu Shirai: Exciton-exciton scattering studied by time-resolved cyclotron resonance, International Conference on Correlation Effects in Radiation Fields (Rostock, Germany, September 12, 2011).
  21. Rico Schwartz, Nobuko Naka, Dietmar Froehlich, Jan Brandt, Christian Sandfort, and Heinrich Stolz: Ultra low temperature thermodynamics and spectroscopy of excitons in cuprous oxide confined in potential traps, NOEKS10 (Paderborn, Germany, August 16, 2010).
  22. Hajime Hirabayashi, Nobuko Naka, Koichiro Tanaka, Makoto Kuwata-Gonokami: Three-dimensional Raman imaging of diamond nanotips, Yuri P. Svirko, and Alexander N. Obraztsov, International Workshop "Nanocarbon Photonics and Optoelectronics"(Koli, Finland, August 5, 2010).
  23. N. Naka, I. Akimoto, M. Shirai, and K. Kan’no: Cyclotron resonance in cuprous oxide studied in a time-resolved regime, ICPS2010 (Seoul, Korea, July 30, 2010).
  24. J. Omachi, T. Suzuki, N. T. Long, K. Yoshioka, N. Naka, and M. Kuwata-Gonokami: Mid-infrared dielectric response of electron-hole droplets in diamond, EXCON’10 (Brisbane, Australia, July 13, 2010).
  25. Nobuko Naka: 半導体における高密度電子正孔系の光制御 (光ナノサイエンス特別講義,奈良先端科学技術大学院大学物質創成科学研究科,November 10, 2009).
  26. Nobuko Naka: High-density electron-hole systems in an indirect-gap semiconductor (University of Konstanz, Germany, August 15, 2008).
  27. N. Naka, J. Omachi, T. Sakamoto, M. Kuwata-Gonokami, K. Tamasaku, T. Ishikawa and H. Sumiya: Decaytimes of free excitons in synthesized high-purity diamond crystals, NPO2008 (Joensuu, Finland, August 8, 2008).
  28. N. Naka, T. Kitamura, J. Omachi, and M. Kuwata-Gonokami: Low-temperature excitons produced by two-photon excitation in high-purity diamond crystals, EXCON08 (Kyoto, Japan, July 24, 2008).
  29. E. Chae, K. Yoshioka, T. Ideguchi, N. Naka and M. Kuwata-Gonokami: Cu2O paraexcitons in a strain-induced trap probed by excitonic Lyman spectroscopy, EXCON08 (Kyoto, Japan, July 24, 2008).
  30. Nobuko Naka: High-density electron-hole systems in direct and indirect-gap semiconductors (University of Rostock, Germany, October 24, 2007).
  31. N. Naka: High-density electron-hole systems in direct-gap and indirect-gap semiconductors, International mini-symposium on high-density excitation of excitons in Cu2O: Chances for Bose-Einstein condensation? (Dortmund, Germany, July 30, 2007).
  32. Nobuko Naka, Junko Omachi, and Makoto Kuwata-Gonokami: Suppressed formation of electron-hole droplets in diamond under strain, 71 Annual Meeting of the Deutsche Physikalische Gesellschaft (Regensburg, Germany, March 28, 2007).
  33. Nobuko Naka: High-resolution spectroscopy of excitons in cuprous oxide under magnetic field, Zernike Seminar (University of Groningen, Netherlands, March 6, 2007).
  34. N. Naka, J. Omachi, and M. Kuwata-Gonokami: Suppression of electron-hole-droplet phase in diamond by strain field, 3rd International Conference on Spontaneous Coherence in Excitonic Systems (Les Houches, France, January 17, 2007).
  35. N. Naka: Strain-confined excitons in cuprous oxide, EII Group seminar, (University of Dortmund, December 2, 2005).
  36. N. Naka: Bosonic stimulation of cold excitons in a harmonic trap in Cu2O, Sonderseminar, Materialeigenschaften und Konzepte zur Quanteninformations- verarbeitung (University of Dortmund, July 2004).