<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
Уважаемые коллеги!<br>
<br>
В пятницу 12 ноября в 11:30 состоится коллоквиум с докладом:<br>
<br>
John Chalker (Physics Department, University of Oxford)<br>
<font size="4"><b>Many-body delocalisation as symmetry breaking</b></font><br>
<br>
<div class="abstract tex"> I will start this talk with an overview
of recent work on quantum dynamics in many body systems far from
equilibrium. This work has led to an understanding from the
perspective of quantum information, of how a such systems may
approach an equilibrium state at long times, in which initial
conditions are effectively forgotten. It has also led to an
appreciation that there are classes of system in which an
equilibrium state is not reached at long times. One of these
classes is made up of many-body localised systems, in which
randomness in the Hamiltonian is responsible for a long-lived
memory of the initial state of a system. By varying the strength
of randomness, a transition can be induced between localised and
ergodic phases, which seems very different from conventional
symmetry-breaking phase transitions. <br>
In the second part of the talk I will discuss minimal models for
quantum chaos and many-body localisation. The models are Floquet
quantum circuits for lattice spin systems, in which time evolution
is generated by unitary gates that couple neighbouring sites. In
particular, I will examine the circumstances in which a version of
the so-called diagonal approximation (originally developed for the
semiclassical limit in low-dimensional chaotic systems) can be
applied to these systems. Within this framework I will show that
the many-body delocalisation transition can be seen as a form of
symmetry breaking transition, having many of the features
generally associated with conventional phase transitions in
classical statistical mechanical models. <br>
</div>
<br>
ID и пароль онлайн-трансляции в Zoom те же, что и для предыдущих
трансляций докладов на Ученом совете:<br>
<div class="moz-cite-prefix"> <a class="moz-txt-link-freetext"
href="https://zoom.us/j/96899364518?pwd=MzBsR2lYT0lYL2x2b1oyNU9LeWlWUT09">https://zoom.us/j/96899364518?pwd=MzBsR2lYT0lYL2x2b1oyNU9LeWlWUT09</a><br>
Meeting ID: 968 9936 4518<br>
Пароль: 250319 </div>
<br>
Для приезда в Институт можно воспользоваться автобусом, который
будет организован по записи при числе желающих не менее 5. <br>
Для записи на автобус из Москвы в Черноголовку необходимо до 18:00
четверга отправить письмо на адрес электронной почты <a
class="moz-txt-link-abbreviated moz-txt-link-freetext"
href="mailto:bus@itp.ac.ru">bus@itp.ac.ru</a>. После этого
записавшимся до 20:00 поступит подтверждение об отправке или
неотправке автобуса в зависимости от числа записавшихся. <br>
Запись на обратный автобус - как и раньше на Ученом совете.<br>
<br>
</body>
</html>