CPM Seminar

Universal detector efficiency of a mesoscopic capacitor

Simon Nigg

University of Geneva

In this talk I will discuss a novel type of high frequency quantum detector based on the mesoscopic capacitor recently realized by Gabelli et al., [1], which consists of a quantum dot connected via a single channel quantum point contact to a single lead. I will show that the state of a double quantum dot charge qubit capacitively coupled to this detector can be read out in the GHz frequency regime with near quantum limited efficiency. To leading order, the quantum efficiency is found to be universal owing to the universality of the charge relaxation resistance of the mesoscopic capacitor.

References:
[1] J. Gabelli et al., Science 313, 499 (2006)