From sakr at itp.ac.ru Sun May 12 21:46:15 2019 From: sakr at itp.ac.ru (Serge Krashakov) Date: Sun, 12 May 2019 21:46:15 +0300 Subject: [Landau ITP Seminars] Friday 17.05.2019 Message-ID: <005b41c2-e5cf-f79f-820d-9958320d5e63@itp.ac.ru> Уважаемые сотрудники ИТФ, На заседании Ученого совета в пятницу 17 мая 2019 года будут заслушаны доклады: 1) Константин Алешкин *Специальная Кэлерова геометрия и теории Ландау-Гинзбурга* Доклад по теме представляемой к защите кандидатской диссертации. 2) Олег Андреев (короткий доклад) *Aspects of quarkonium propagation in a thermal medium as seen by string models* We use gauge/string duality to model a heavy quark-antiquark pair in a color singlet moving through a thermal plasma. In particular, we explore the effect of velocity on the string tension and Debye screening mass. Then we apply the results to the analysis of heavy quarkonium bound states. With some assumptions, we estimate the characteristic size of quarkonium and its dissociation temperature. -------------- next part -------------- An HTML attachment was scrubbed... URL: From fominov at landau.ac.ru Mon May 20 10:38:31 2019 From: fominov at landau.ac.ru (Yakov Fominov) Date: Mon, 20 May 2019 10:38:31 +0300 Subject: [Landau ITP Seminars] =?utf-8?b?0KHQtdC80LjQvdCw0YAg0LIg0JjQpNCf?= =?utf-8?b?OiDRh9C10YLQstC10YDQsyAyMyDQvNCw0Y8=?= In-Reply-To: References: Message-ID: An HTML attachment was scrubbed... URL: From sakr at itp.ac.ru Mon May 20 11:27:51 2019 From: sakr at itp.ac.ru (Serge Krashakov) Date: Mon, 20 May 2019 11:27:51 +0300 Subject: [Landau ITP Seminars] Friday 24.05.2019 Message-ID: <72aea72d-aded-811e-5331-d79aed091ee3@itp.ac.ru> Уважаемые сотрудники ИТФ, В пятницу 24 мая состоится коллоквиум, на котором будет заслушан доклад: D. Christian Glattli (CEA Saclay, France) *Minimal excitations states: From time resolved single particle fermionic states for Electron Quantum Optics to Digital communication and music.* In the 90’s, an impressive series of works by theoreticians from the Landau Institute on electrons shot noise in quantum conductors [1] and on the statistics of transfer of electrons [2] has leaded to the emergence of the beautiful concept of minimal excitation states [3-5]. These minimal excitation states can be generated by applying voltage pulses on the contact of a conductor to inject short single electron pulses. These states show minimal noise and provide a convenient and clean single electron source for electron optics whose aim is to perform quantum optics tasks with electrons instead of photons. The minimal excitations states, now called levitons, have been produced in recent experiments [6] and have triggered a large number of theoretical works. They have enabled Hong Ou Mandel like experiments [6] with electrons and single electron quantum Tomography [7]. Extension to fractionally charged anyons is possible. At the root of the minimal excitation property is a specific single side band modulation of the electron wave by the Lorentzian voltage pulse. This property can be applied to classical electromagnetic or acoustic waves for applications in digital communication [8] or in music sound synthesis. [1] G. B. Lesovik, JETP Letters, 49 (9), 592-594 (1989). [2] L.S. Levitov, G.B. Lesovik, Charge-transport statistics in quantum conductors, JETP Lett., 55 (9), 555-559 (1992). [3] A. Ivanov, H.W. Lee, L.S. Levitov, Coherent states of alternating current, Phys. Rev. B 56(11), 6839-6850 (1997); cond-mat/9501040 [4] L.S. Levitov, H. Lee, G.B. Lesovik, Electron Counting Statistics and Coherent States of Electric Current, J. Math. Phys., 37(10), 4845-4866 (1996); cond-mat/9607137. [5] J. Keeling, I. Klich, and L. S. Levitov, Minimal Excitation States of Electrons in One-Dimensional Wires, Phys. Rev. Lett. 97, 116403 (2006). [6] Minimal-excitation states for electron quantum optics using levitons, J. Dubois, T. Jullien, F. Portier, P. Roche, A. Cavanna, Y. Jin, W. Wegscheider, P. Roulleau & D. C. Glattli, Nature, 502, 659–663 (2013). [7] Quantum tomography of an electron, T. Jullien, P. Roulleau, B. Roche, A. Cavanna, Y. Jin & D. C. Glattli, Nature, 514, 603–607 (2014). [8] Power Spectrum Density of Single Side Band CPM Using Lorenztian Frequency Pulses, Haïfa Farès, D. Christian Glattli, Yves Louet, Jacques Palicot, Preden Roulleau, and Christophe Moy, IEEE Wireless Communications Letters, 6 (6), 786-789 (2017). -------------- next part -------------- An HTML attachment was scrubbed... URL: From fominov at landau.ac.ru Fri May 24 14:18:38 2019 From: fominov at landau.ac.ru (Yakov Fominov) Date: Fri, 24 May 2019 14:18:38 +0300 Subject: [Landau ITP Seminars] =?utf-8?b?0KHQtdC80LjQvdCw0YAg0LIg0JjQpNCf?= =?utf-8?b?OiDRh9C10YLQstC10YDQsyAzMCDQvNCw0Y8=?= Message-ID: An HTML attachment was scrubbed... URL: From sakr at itp.ac.ru Tue May 28 00:21:16 2019 From: sakr at itp.ac.ru (Serge Krashakov) Date: Tue, 28 May 2019 00:21:16 +0300 Subject: [Landau ITP Seminars] Friday 31.05.2019 Message-ID: Уважаемые сотрудники ИТФ, На заседании Ученого совета ИТФ в пятницу 31 мая будут заслушаны доклады: 1) _Парфеньев В.М._, Филатов С.В., Бражников М.Ю., Вергелес С.С., Левченко А.А. *Формирование и затухание вихревых течений, генерируемых скрещенными поверхностными волнами** * The mass-transport induced by crossed surface waves consists of the Stokes and Euler contributions which are very different in nature. The first contribution is a generalization of Stokes drift for a plane wave in ideal fluid and the second contribution arises due to the fluid viscosity and it is excited by a force applied in the viscous sublayer near the fluid surface. We study the formation and decay of the induced mass-transport theoretically and experimentally and demonstrate that both contributions have different time scales for typical experimental conditions. The evolution of the Euler contribution is described by a diffusion equation, where the fluid kinematic viscosity plays the role of the diffusion coefficient, while the Stokes contribution evolves faster, feeling the additional damping near the system boundaries. The difference becomes more pronounced if the fluid surface is contaminated. We model the effect of contamination by a thin insoluble liquid film presented on the fluid surface with the compression modulus being the only non-zero rheological parameter of the film. Then the Euler contribution into the mass-transport becomes parametrically larger and the evolution of the Stokes contribution becomes parametrically faster. The parameter is the same in both cases and it is equal to the quality factor of surfaces waves, which is modified by the presence of a surface film. We infer the value of the compression modulus of the film by fitting the results of transient measurements of eddy currents and demonstrate that the obtained value leads to the correct ratio of amplitudes of horizontal and vertical velocities of the wave motion and is in reasonable agreement with the measured dissipation rate of surface waves. 2) С.А. Белан *Эксперимент Бернулли с перезапуском* Как известно, перезапуск стохастического процесса может существенно сократить среднее время требуемое для его завершения. Этот эффект широко применяется для ускорения стохастических алгоритмов поиска и потенциально может быть использован для повышения скорости протекания химических реакций. Однако, в ряде случаев интерес представляет не длительность процесса, а то по какому сценарию этот процесс завершился. В докладе будет показано, как перезапуск влияет на вероятности реализации различных исходов стохастических процессов типа эксперимента Бернулли, то есть процессов с двумя альтернативными сценариями завершения. Особое внимание будет уделено классу задач, где специальным образом подобранная частота перезапуска максимизирует шансы на получение желаемого исхода. Проведенный анализ демонстрирует, что оптимально перезапускаемые процессы обладают рядом универсальных особенностей. -------------- next part -------------- An HTML attachment was scrubbed... URL: