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Seminar on Theoretical and Computational Physics:
TitleThe Interacting Mesoscopic Capacitor: from the quantum RC-circuit to out-of-equilibrium charge emission
SpeakerDr. Michele Filippone
AffiliationUniversité de Genève
DateFriday, 11-08-2017
Time10:30 AM
LocationRoom 202 (Library), Institute of Physics, 10 Dao Tan, Ba Dinh, Hanoi
AbstractThe mesoscopic capacitor was realized for the first time at the Laboratoire Pierre Aigrain (LPA) of Paris in 2006. Since then, it revealed a formidable platform to achieve the triggered emission of single electrons and realize highly controlled quantum optics experiments with electrons in solid state devices. I will discuss the main challenges concerning the theoretical description of this system and go beyond the quantum RC-circuit analogy by describing the full non-equilibrium response of a mesoscopic capacitor in the large transparency limit, exactly solving a model with electron-electron interactions appropriate for a cavity in the quantum Hall regime. For a cavity coupled to the electron reservoir via an ideal point contact, we show that the response to any time-dependent gate voltage V_g(t) is strictly linear in V_g. We analyze the charge and current response to a sudden gate voltage shift, and find that this response is not captured by a simple circuit analogy. In particular, in the limit of strong interactions a sudden change in the gate voltage leads to the emission of a sequence of multiple charge pulses, the width and separation of which are controlled by the charge-relaxation time τ_c=hC_g/e^2 and the time of flight τ_f. We also consider the effect of a finite reflection amplitude in the point contact, which leads to non-linear-in-gate-voltage corrections to the charge and current response.
Host personNguyễn Thị Kim Thanh