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<div><span>Уважаемые коллеги!</span></div>
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<div><span>На заседании Ученого совета ИТФ в пятницу 03.10 будет заслушан доклад:</span></div>
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<div><strong>11:30 </strong></div>
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<div><strong>M. A. Skvortsov, A. V. Polkin</strong></div>
<div><strong>Thermal phase slips in superconducting films and Boussinesq equation</strong></div>
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<div><span>A dissipationless supercurrent state in superconductors can be destroyed by thermal fluctuations. Thermally activated phase slips provide a finite resistance of the sample and are responsible for dark counts in superconducting single photon detectors. The activation barrier for a phase slip is determined by a space-dependent saddle-point (instanton) configuration of the order parameter. In the one-dimensional wire geometry, such a saddle point has been analytically obtained by Langer and Ambegaokar in the vicinity of the critical temperature, $T_c$, and for arbitrary bias currents below the critical current $I_c$. In the two-dimensional geometry of a superconducting strip, which is relevant for photon detection, the situation is much more complicated. Depending on the ratio $I/I_c$, several types of saddle-point configurations have been proposed, with their energies being obtained numerically. We demonstrate that the saddle-point configuration for an infinite superconducting film at $I\to I_c$ is described by the exactly integrable Boussinesq equation solved by Hirota's method. The instanton size is $L_x\sim\xi(1-I/I_c)^{-1/4}$ along the current and $L_y\sim\xi(1-I/I_c)^{-1/2}$ perpendicular to the current, where $\xi$ is the Ginzburg-Landau coherence length. The activation energy for thermal phase slips scales as $\Delta F^\text{2D}\propto (1-I/I_c)^{3/4}$. For sufficiently wide strips of width $w\gg L_y$, a half-instanton is formed near the boundary, with the activation energy being 1/2 of $\Delta F^\text{2D}$.</span></div>
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<div><span>ID и пароль онлайн-трансляций в Zoom те же, что и для предыдущих трансляций семинаров и докладов на Ученом совете:</span></div>
<div><span>https://zoom.us/j/96899364518?pwd=MzBsR2lYT0lYL2x2b1oyNU9LeWlWUT09</span></div>
<div><span>Meeting ID: 968 9936 4518</span></div>
<div><span>Пароль: 250319</span></div>
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<div style="font-size: 13.3333px; font-family: Verdana, Geneva, sans-serif;"><strong>Просьба присутствовать на заседании членов Учёного совета в связи с голосование открытым, поднятием "виртуальной" руки. </strong></div>
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<p><span style="font-size: 13px; font-family: monospace; background-color: #ffffff;"><strong>На завтра 03.10.25г. в 10-05 автобус запланирован</strong>.</span><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><span style="font-size: 13px; font-family: monospace; background-color: #ffffff;">Место сбора 11-я парковая, поворот на Щелковское шоссе.</span><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><span style="font-size: 13px; font-family: monospace; background-color: #ffffff;">Форд-Транзит А 797МА 150</span><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><span style="font-size: 13px; font-family: monospace; background-color: #ffffff;">тел. 8-903-019-86-80</span><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><span style="font-size: 13px; font-family: monospace; background-color: #ffffff;">Владимир Николаевич</span><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><a style="color: #00acff; font-size: 13px; font-family: monospace; background-color: #ffffff;" href="https://yandex.ru/maps/213/moscow/?from=mapframe&indoorLevel=1&ll=37.804151%2C55.809870&mode=usermaps&source=mapframe&um=constructor%3A1gjtTU9HvRzE3mvpCCP6B_Io424BFoMD&utm_source=mapframe&z=17.4" target="_blank" rel="noopener noreferrer">https://yandex.ru/maps/213/moscow/?from=mapframe&indoorLevel=1&ll=37.804151%2C55.809870&mode=usermaps&source=mapframe&um=constructor%3A1gjtTU9HvRzE3mvpCCP6B_Io424BFoMD&utm_source=mapframe&z=17.4</a><span style="font-size: 13px; font-family: monospace; background-color: #ffffff;"></span><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /><br style="font-size: 13px; font-family: monospace; background-color: #ffffff;" /></p>
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