Violation of Kirchhoff's Laws for a Coherent RC Circuit

Julien Gabelli (1) , Gwendal Fève (1) , Jean-Marc Berroir (1) , Bernard Plaçais (1) , A. Cavanna (2) , Bernard Etienne (2) , Yong Jin (2) , Christian D.C. Glattli (1, 3)

1 LPA - Laboratoire Pierre Aigrain
2 LPN - Laboratoire de photonique et de nanostructures
3 SPEC - UMR3680 - Service de physique de l'état condensé

What is the complex impedance of a fully coherent quantum resistance-capacitance (RC) circuit at GHz frequencies in which a resistor and a capacitor are connected in series? While Kirchhoff's laws predict addition of capacitor and resistor impedances, we report on observation of a different behavior. The resistance, here associated with charge relaxation, differs from the usual transport resistance given by the Landauer formula. In particular, for a single mode conductor, the charge relaxation resistance is half the resistance quantum, regardless of the transmission of the mode. The new mesoscopic effect reported here is relevant for the dynamical regime of all quantum devices.

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Julien Gabelli, Gwendal Fève, Jean-Marc Berroir, Bernard Plaçais, A. Cavanna, et al.. Violation of Kirchhoff's Laws for a Coherent RC Circuit. Science, 2006, 313, pp.499. ⟨hal-00108295⟩