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arXiv · 1405.3085

Evaluating charge noise acting on semiconductor quantum dots in the circuit quantum electrodynamics architecture

Julien Basset·Anna Stockklauser·David-Dominik Jarausch·Tobias Frey·Christian Reichl·Werner Wegscheider·Andreas Wallraff·Klaus Ensslin·Thomas Ihn
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Abstract

We evaluate the charge noise acting on a GaAs/GaAlAs based semiconductor double quantum dot dipole-coupled to the voltage oscillations of a superconducting transmission line resonator. The in-phase ($I$) and the quadrature ($Q$) components of the microwave tone transmitted through the resonator are sensitive to charging events in the surrounding environment of the double dot with an optimum sensitivity of $8.5\times10^{-5} \mbox{e}/\sqrt{\mbox{Hz}}$. A low frequency $1/f$ type noise spectrum combined with a white noise level of $6.6\times10^{-6}$ $\mbox{e}^2/\mbox{Hz}$ above $1$ Hz is extracted, consistent with previous results obtained with quantum point contact charge detectors on similar heterostructures. The slope of the $1/f$ noise allows to extract a lower bound for the double-dot charge qubit dephasing rate which we compare to the one extracted from a Jaynes-Cummings Hamiltonian approach. The two rates are found to be similar emphasizing that charge noise is the main source of dephasing in our system.

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Julien Basset, Anna Stockklauser, David-Dominik Jarausch, Tobias Frey, Christian Reichl, Werner Wegscheider, Andreas Wallraff, Klaus Ensslin, Thomas Ihn. 2014-05-13. Evaluating charge noise acting on semiconductor quantum dots in the circuit quantum electrodynamics architecture. https://doi.org/10.1063/1.4892828

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