Семинар международной лаборатории физики конденсированного состояния (совместно с теоретическим семинаром ИФП РАН): D. A. Bandurin (University of Manchester) "Electron hydrodynamics in graphene: introduction and status"
В четверг 17 мая 2018 в 11:30
состоится научный семинар Международной лаборатории физики конденсированного состояния НИУ ВШЭ совместно с теоретическим семинаром ИФП им. П.Л. Капицы РАН
D. A. Bandurin
(School of Physics & Astronomy, University of Manchester, UK)
Electron hydrodynamics in graphene: introduction and status
Abstract:
Transport in systems with many particles experiencing frequent mutual collisions (such as gases or liquids) has been studied for more than two centuries and is accurately described by the theory of hydrodynamics. It has been argued theoretically for a long time that the collective behavior of charge carriers in solids can also be treated by the hydrodynamic approach. However, despite many attempts, very little evidence of hydrodynamic electron transport has been found so far.
Graphene encapsulated between hexagonal boron nitride (hBN) offers an ideal platform to study electron hydrodynamics as it hosts an ultra-clean electronic system with the electron-electron mean free path being the shortest lengths scale in the problem. In the first part of my talk we will discuss why electron hydrodynamics has not been observed before and how it manifests itself in electron transport. Furthermore, it will be shown that electrons in graphene can behave as a very viscous fluid (more viscous than honey) forming vortices of applied electron current [1]. In the second part, we will discuss the measurements of the viscosity of an electron fluid by its superballistic flow through graphene point contacts [2]. Then we will talk about the behavior of electron fluids in the presence of magnetic field where I will report the experimental measurements of the Hall viscosity in two dimensions [3]. This dissipationless transport coefficient has been widely discussed in theoretical literature on fluid mechanics, plasma physics and condensed matter physics, yet, until now, any experimental evidence has been lacking, making the phenomenon truly a unicorn. Last but not least, we will discuss how electron hydrodynamics can be used for the development of resonant terahertz photodetectors.
[1] D.A. Bandurin, A. Principi, G.H. Auton, E. Khestanova, K.S. Novoselov, I.V Grigorieva, L.A. Ponomarenko, A.K. Geim, and M. Polini, Science 351, 1055 (2016).
[2] R.K. Kumar, D.A. Bandurin, F.M.D. Pellegrino, Y. Cao, A. Principi, H. Guo, G.H. Auton, M. Ben Shalom, L.A. Ponomarenko, G. Falkovich, I.V. Grigorieva, L.S. Levitov, M. Polini, and A.K. Geim, Nat. Phys. 13, 1182 (2017).
[3] A.I. Berdyugin, S.G. Xu, F.M.D. Pellegrino, R. Krishna Kumar, A. Principi, I. Torre, M. Ben Shalom, T. Taniguchi, K. Watanabe, I.V. Grigorieva, M. Polini, A.K. Geim, and D.A. Bandurin, to appear on arxiv soon.
Семинар пройдет в конференц-зале Института физических проблем по адресу:
ул. Косыгина 2, 2-ой этаж.
Как добраться до ИФП и конференц-зала, описано здесь.
Вход свободный.
Начало в 11:30.