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Photoluminescent carbon nanotubes are expected to become versatile room-temperature single-photon sources that have applications in quantum information processing. Quantum emission from carbon nanotubes is often induced by localization of…

Mesoscale and Nanoscale Physics · Physics 2021-11-18 Zhen Li , Keigo Otsuka , Daiki Yamashita , Daichi Kozawa , Yuichiro K. Kato

We report that dark excitons can have a large contribution to the emission intensity in carbon nanotubes due to an efficient exciton conversion from a dark state to a bright state. Time-resolved photoluminescence measurements are used to…

Mesoscale and Nanoscale Physics · Physics 2019-12-11 A. Ishii , H. Machiya , Y. K. Kato

It is strong Coulomb effects in carbon nanotubes that lead to formation of the so-called "bright" and "dark" (forbidden one-photon optical transition) exciton states, and dramatically decrease the efficiency of one-photon light emission via…

Quantum Physics · Physics 2009-02-09 Nikolai G. Kalugin , Yuri V. Rostovtsev

Single-walled carbon nanotubes (SWCNTs) are promising absorbers and emitters to enable novel photonic and optoelectronic applications but are also known to severely suffer from low optical quantum yields. Here we demonstrate SWCNTs excitons…

Mesoscale and Nanoscale Physics · Physics 2017-12-20 Yue Luo , Ehsaneh D. Ahmadi , Kamran Shayan , Yichen Ma , Kevin S. Mistry , Changjian Zhang , James Hone , Jeffrey L. Blackburn , Stefan Strauf

Condensed-matter emitters offer enriched cavity quantum electrodynamical effects due to the coupling to external degrees of freedom. In the case of carbon nanotubes a very peculiar coupling between localized excitons and the one-dimensional…

We report optical studies of quantum dot excitons in individual suspended carbon nanotubes at cryogenic temperatures. Narrow optical linewidths, strongly suppressed spectral wandering, and photoluminescence lifetimes in the range of…

Mesoscale and Nanoscale Physics · Physics 2014-10-03 Matthias S. Hofmann , Jan T. Glückert , Alexander Högele

Luminescence properties of carbon nanotubes are strongly affected by exciton diffusion, which plays an important role in various nonradiative decay processes. Here we perform photoluminescence microscopy on hundreds of individual…

Mesoscale and Nanoscale Physics · Physics 2015-03-23 A. Ishii , M. Yoshida , Y. K. Kato

Photonic crystal nanocavities are used to enhance photoluminescence from single-walled carbon nanotubes. Micelle-encapsulated nanotubes are deposited on nanocavities within Si photonic crystal slabs and confocal microscopy is used to…

Mesoscale and Nanoscale Physics · Physics 2012-10-12 R. Watahiki , T. Shimada , P. Zhao , S. Chiashi , S. Iwamoto , Y. Arakawa , S. Maruyama , Y. K. Kato

Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature and as nanoscale light sources for integrated photonic circuits on silicon. Here we show that integration of dopant states in carbon…

Mesoscale and Nanoscale Physics · Physics 2018-08-24 A. Ishii , X. He , N. F. Hartmann , H. Machiya , H. Htoon , S. K. Doorn , Y. K. Kato

Statistics of photons emitted by mobile excitons in individual carbon nanotubes are investigated. Photoluminescence spectroscopy is used to identify the chiralities and suspended lengths of air-suspended nanotubes, and photon correlation…

Mesoscale and Nanoscale Physics · Physics 2017-11-28 A. Ishii , T. Uda , Y. K. Kato

We present theoretical analysis and first-principles calculation of the radiative lifetime of excitons in semiconducting carbon nanotubes. An intrinsic lifetime of the order of 10 ps is computed for the lowest optically active bright…

Materials Science · Physics 2009-11-11 Catalin D. Spataru , Sohrab Ismail-Beigi , Rodrigo B. Capaz , Steven G. Louie

The bright exciton emission of semiconducting carbon nanotubes is appealing for optoelectronic and quantum photonic devices as well as fundamental studies of light-matter interaction in one-dimensional nanostructures. The photophysics of…

Mesoscale and Nanoscale Physics · Physics 2017-05-09 Ibrahim Sarpkaya , Zhengyi Zhang , William Walden-Newman , Xuesi Wang , James Hone , Chee Wei Wong , Stefan Strauf

Simultaneous photoluminescence and photocurrent measurements on individual single-walled carbon nanotubes reveal spontaneous dissociation of excitons into free electron-hole pairs. Correlation of luminescence intensity and photocurrent…

Mesoscale and Nanoscale Physics · Physics 2014-03-19 Y. Kumamoto , M. Yoshida , A. Ishii , A. Yokoyama , T. Shimada , Y. K. Kato

We report on high efficency coupling of individual air-suspended carbon nanotubes to silicon photonic crystal nanobeam cavities. Photoluminescence images of dielectric- and air-mode cavities reflect their distinctly different mode profiles…

Mesoscale and Nanoscale Physics · Physics 2014-11-27 R. Miura , S. Imamura , R. Ohta , A. Ishii , X. Liu , T. Shimada , S. Iwamoto , Y. Arakawa , Y. K. Kato

We have demonstrated an up to seven-fold enhancement of photoluminescence from silicon-rich silicon nitride film due to a single photonic crystal cavity. The enhancement is partially attributed to the Purcell effect. Purcell factor…

Optics · Physics 2007-05-23 Maria Makarova , Jelena Vuckovic , Hiroyuki Sanda , Yoshio Nishi

Single air-suspended carbon nanotubes (length 2 - 5 microns) exhibit high optical quantum efficiency (7 - 20%) for resonant pumping at low intensities. Under ultrafast excitation, the photoluminescence dramatically saturates for very low…

Materials Science · Physics 2010-01-14 Y. -F. Xiao , T. Q. Nhan , M. W. B. Wilson , J. M. Fraser

We calculate the radiative lifetime and energy bandstructure of excitons in semiconducting carbon nanotubes, within a tight-binding approach. In the limit of rapid interband thermalization, the radiative decay rate is maximized at…

Materials Science · Physics 2015-06-25 Vasili Perebeinos , J. Tersoff , Phaedon Avouris

At cryogenic temperature and at the single emitter level, the optical properties of single-wall carbon nanotubes depart drastically from that of a one-dimensional (1D) object. In fact, the (usually unintentional) localization of excitons in…

Highly efficient exciton-exciton annihilation process unique to one-dimensional systems is utilized for super-resolution imaging of air-suspended carbon nanotubes. Through the comparison of fluorescence signals in linear and sublinear…

Mesoscale and Nanoscale Physics · Physics 2019-06-12 K. Otsuka , A. Ishii , Y. K. Kato

We report a numerical design procedure for pursuing a near-unity coupling efficiency in quantum dot-cavity ridge waveguide single-photon sources by performing simulations with the finite element method. Our optimum design which is based on…

Optics · Physics 2022-12-21 Yujing Wang , Luca Vannucci , Sven Burger , Niels Gregersen
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