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We present a recursive method for calculating
zero-frequency current cumulants of very high or-
ders for quantum stochastic processes described
by non-Markovian generalized master equations
(GME) [1,2]. Within the same framework, the
finite-frequency noise can also be evaluated. As
a specific example, we consider charge transport
through two coherently coupled Coulomb blockade
quantum dots embedded in a dissipative environ-
ment. For high orders, the cumulants show surpri-
sing oscillations as functions of the level detuning.
Using mathematical properties of derivatives in the complex plane [3] we show that these oscillations are in fact universal and are expected to occur as functions of almost any parameter in a wide class of stochastic processes [4]. We present the first experimental evidence of universal oscillations in electron transport through a single quantum dot [4]. [1] C. Flindt, T. Novotný, A. Braggio, M. Sassetti, and A.-P. Jauho, Phys. Rev. Lett. 100, 150601 (2008) [2] C. Flindt, T. Novotný, A. Braggio, and A.-P. Jauho, in preparation (2008) [3] M. V. Berry, Proc. R. Soc. A 461, 1735 (2005) [4] C. Flindt, C. Fricke, F. Hohls, T. Novotný, K. Netočný, T. Brandes, and R. J. Haug, submitted (2008) |