Olga A. Dyatlova
Postdoc
Westfälische Wilhelmsuniversität
Physikalisches Institut
Wilhelm-Klemm-Strasse 10
48149 Münster, Germany
Phone:+49 (0)251 83-25336
e-mail: olga.dyatlova@uni-muenster.de
Employment/Education
| October 2008- December 2013 |
TU Berlin University, IOAP PhD student/ scientific employee with teaching obligation in the group of Prof. Dr. Ulrike Woggon Preliminary title of thesis: “Nonlinear optics with nanostructured semiconductors” |
Berlin, Germany |
| March 2007- September 2008 |
TU Dortmund University, Experimental Physics II Guest scientist in the group of Prof. Dr. Ulrike Woggon Research subject: “Optical properties of semiconductor nanocrystals” |
Dortmund, Germany |
| 25 January 2008 | St. Petersburg State University, Faculty of Physics, Solid State Physics Department Master of Science in physics Supervisor: Dr. I. H. Akopyan Title of thesis: “Crystal structure of copper halides in photochromic glass” |
St. Petersburg, Russia |
| 3 June 2005 | St. Petersburg State University, Faculty of Physics, Solid State Physics Department Bachelor of Science in physics Supervisor: Dr. I. H. Akopyan Title of thesis: “Size quantization of the electronic states in semiconductor nanocrystals” |
St. Petersburg, Russia |
| September 2001- January 2008 |
St. Petersburg State University, Faculty of Physics, Solid State Physics Department Student |
St. Petersburg, Russia |
Languages: Russian (native speaker), English (good), German (basics)
Research Publication
Dielectric screening effects on transition energies in aligned carbon nanotubes
Olga A. Dyatlova, Jordi Gomis-Bresco, Ermin Malic, Hagen Telg, Janina Maultzsch, Guofang Zhong, Junfeng Geng, Ulrike Woggon
Physical Review B, Volume: 85, Issue: 24, Article Number: 245449/ June 2012
Abstract: The optical transition energies Eii of carbon nanotubes (CNTs) strongly depend on the dielectric function εq of the nanotubes and the dielectric background constant ebg of their surroundings. It becomes particularly evident when CNTs in solution and free-standing, vertically aligned CNTs are compared via their optical spectra. Using photoluminescence-excitation spectroscopy, we determine the first two transition energies for these two types of carbon-nanotube samples, i.e., for CNT-solution and CNT-forest samples. We observe considerable energy shifts and explain them by microscopic calculations based on the density-matrix formalism. Combining experiment and theory, we determine the dielectric background constant of the CNT-forest and CNT-solution samples to be 1.3 ± 0.1 and 1.8 ± 0.1, respectively.
Scattering of electrons with acoustic phonons in single-walled carbon nanotubes
Olga A. Dyatlova, Christopher Köhler, Ermin Malic, Jordi Gomis-Bresco, Janina Maultzsch, Andrey Tsagan-Mandzhiev, Tobias Watermann, Andreas Knorr, Ulrike Woggon
2012 Conference on Lasers and Electro-Optics (CLEO)/ May 2012
Abstract: We perform two-color pump-probe experiments on (8,7), (10,2). (11,3) and (12,1) tubes. The density matrix formalism reveals that the measured few picosecond component of the relaxation dynamics is due to intraband carrier-acoustic phonon scattering.
Compact Electrically Tunable Delay Generator on Silicon
Kambiz Jamshidi, Stefan Meister, Bulent Andreas Franke, Olga Dyatlova, Aws Al-saadi, Ulrike Woggon, Hans Joachim Eichler, Thomas Schneider
2012 Conference on Lasers and Electro-Optics (CLEO)/ May 2012
Abstract: Feasibility of a tunable delay of optical data streams is proved by experimentally validating a hybrid fiber/integrated realization. Ultimate design can provide delays of more than 200 ps in an area of about 0.4 mm2.
Ultrafast relaxation dynamics via acoustic phonons in carbon nanotubes
Olga A. Dyatlova, Christopher Köhler, Ermin Malic, Jordi Gomis-Bresco, Janina Maultzsch, Andrey Tsagan-Mandzhiev, Tobias Watermann, Andreas Knorr, Ulrike Woggon
Nano Letters, Volume: 12, Issue: 5, Pages: 2249-2253/ May 2012
Abstract: Carbon nanotubes as one-dimensional nanostructures are ideal model systems to study relaxation channels of excited charged carriers. The understanding of the ultrafast scattering processes is the key for exploiting the huge application potential that nanotubes offer, e.g., for light-emitting and detecting nanoscale electronic devices. In a joint study of two-color pump-probe experiments and microscopic calculations based on the density matrix formalism, we extract, both experimentally and theoretically, a picosecond carrier relaxation dynamics, and ascribe it to the intraband scattering of excited carriers with acoustic phonons. The calculated picosecond relaxation times show a decrease for smaller tube diameters. The best agreement between experiment and theory is obtained for the (8,7) nanotubes with the largest investigated diameter and chiral angle for which the applied zone-folded tight-binding wave functions are a good approximation.
The excitonic capture path in electrically pumped quantum dots using time-resolved amplified spontaneous emission
Jordi Gomis-Bresco, Sabine Dommers-Völkel, Oliver Schöps, Yuecel Kaptan, Olga Dyatlova, Dieter Bimberg, Ulrike Woggon
Applied Physics Letters, Volume: 97, Issue: 25, Article Number: 251106/ December 2010
Abstract: We combine pump and probe and time resolved photoluminescence to determine the excitonic capture path of InGaAs/GaAs quantum dots in-a-well in a semiconductor optical amplifier. We observe a 10 ps delayed excited state population drop-off.
Specific features of the CuI nanocrystal structure in photochromic glasses
I. Kh. Akopyan, V. V. Golubkov, O. A. Dyatlova, A. N. Mamaev, B. V. Novikov, A. N. Tsagan-Mandzhiev
Physics of The Solid State, Volume: 52, Issue: 4, Pages: 805-809/ April 2010
Abstract: The absorption spectra of CuI nanocrystals with an average radii of 5.3 and 6.2 nm in photochromic glass matrix have been studied in the temperature range 38–300 K. It has been established that the copper iodide nanocrystals, like copper chloride and copper bromide nanocrystals of the same sizes, predominantly crystallize in a nonequilibrium form different from the stable low-temperature cubic modification. The structure of metastable modifications of copper halide nanocrystals in photochromic glasses has been discussed.
Structure of copper halide nanocrystals in photochromic glasses
I. Kh. Akopyan, V. V. Golubkov, O. A. Dyatlova, B. V. Novikov and A. N. Tsagan-Mandzhiev
Physics of the Solid State, Volume: 50, Issue: 7, Pages: 1352-1356/ July 2008
Abstract: The crystal structure of CuCl nanocrystals with effective radii ranging from 2.4 to 18.5 nm in photochromic glasses heat treated under different conditions is investigated using exciton spectroscopy, x-ray powder diffraction, and small-angle x-ray scattering. It is revealed that the size dependence of the energy of the Z 3 exciton exhibits an anomalous behaviour. The results obtained suggest that small-sized CuCl nanocrystals can crystallize in a modification different from the stable cubic modification.