Теоретические семинары в ИФП им. П.Л. Капицы
Together we can: transport properties of electron viscous flows
27 апреля в 11:30
Л. Левитов (MIT)
Strongly interacting electrons can move in a neatly coordinated way, reminiscent of the movement of viscous fluids. In viscous electron flows interactions give rise to a collective behavior, facilitating transport and allowing conductance to exceed the fundamental Sharvin-Landauer ballistic limit Gball. This talk will describe a theory of the ballistic-to-viscous crossover in a constriction exhibiting the ballistic transport at T = 0 but governed by electron hydrodynamics at elevated temperatures. An approach based on quasi-hydrodynamic variables predicts an additive relation G = Gball + Gvis, where the viscous contribution Gvis dominates over Gball in the hydrodynamic limit. We will also discuss recent measurements of electron transport through graphene constrictions, finding that conductance below 150 K increases with increasing temperature. The measurements help to identify the conductance contribution arising due to electron viscosity and determine its temperature dependence. Besides fundamental interest, this work shows that viscous effects can facilitate high-mobility transport at elevated temperatures, a potentially useful behavior for designing graphene-based devices.
Семинары проходят по четвергам в конференц-зале Института физических проблем им. П.Л. Капицы РАН, начало в 11:30. Адрес: Москва, ул. Косыгина, д. 2