{"id":92,"date":"2014-04-06T08:57:15","date_gmt":"2014-04-06T06:57:15","guid":{"rendered":"http:\/\/phsites.technion.ac.il\/lindner\/?page_id=92"},"modified":"2020-08-10T12:27:04","modified_gmt":"2020-08-10T09:27:04","slug":"topological-phenomena-non-equilibrium-systems","status":"publish","type":"page","link":"https:\/\/phsites.technion.ac.il\/lindner\/topological-phenomena-non-equilibrium-systems\/","title":{"rendered":"Topological Phenomena in Non-equilibrium Systems"},"content":{"rendered":"\n

Topological Phenomena in Non-equilibrium Systems<\/h1>\n\n\n\n
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The efforts to realize new topological phases have focused mostly on equilibrium systems at zero temperature. The exciting possibility of realizing topological phenomena in out-of-equilibrium systems has been recently proposed in the context systems subjected to periodic external driving forces. A major advantage of this setup is the wider range of experimental controls it allows, and new types of accessible topological states. An intriguing example is the proposal that a non-topological material subject to electromagnetic radiation can have properties that mimic those of a topological insulator; this may open a completely new route to exploring topological phases, which are not accessible in equilibrium setups. Combined with the highly developed technology for controlling low-frequency electromagnetic modes, potential applications such as devices which utilize fast switching of edge state transport might become possible. Following this route, many important questions remain to be explored: What is the nature of topological phenomena in periodically driven systems? What kinds of phases can be realized following this route, and how different are they from the equilibrium ones? How does topology interplay with many-body interactions and the coupling to the environment to determine their properties? In which experimentally accessible systems can they be realized?<\/p>\n

Selected Work<\/h3>\n
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Universal Chiral Quasisteady States in Periodically Driven Many-Body Systems<\/h4>\n

\"Universal Many novel experimental systems, such as cold atom and trapped ion systems, allow us to study the non-equilibrium many-body states of closed, interacting quantum systems subjected to a periodic drive. Generically, such systems are expected to absorb energy and heat up rapidly washing away any interesting quantum, and in particular, topological effects. In this work, we show that the tendency of driven quantum systems to heat up can in fact yield a new universal quantum phenomenon, which persists over a long intermediate time window. In the one dimensional prototype system we study, the universality is manifested in a persistent current, whose magnitude depends only on topological properties of the driving protocol and the density of particles. Quick heating of the low-energy degrees of freedom erases the initial details of the system. The high-energy degrees of freedom, meanwhile, remain cold for a long time, during which the system exhibits its topological properties. Our analysis serves as a prototype for a new class of phenomena that can arise in a variety of driven quantum systems.<\/p>\n