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conferenceseries.com
Volume 4, Issue 3(Suppl) J Laser Opt Photonics, an open access journal
ISSN: 2469-410X Quantum Physics 2017
September 25-26, 2017
September 25-26, 2017 Berlin, Germany
2nd International Conference on
Quantum Physics and
Quantum Technology
Weak and strong non-linear effects in Josephson junction chains
Wiebke Guichard
Université Grenoble-Alpes, France
Iwill present our microwave transmission measurements on propagation modes in Josephson junction chains containing several
hundreds of junctions. After some preliminary measurements we have done a more systematic measurement in an improved
measurement set-up that I will present. Some of the chains have been embedded into the microwave strip line, while others have been
coupled capacitively to it. The latter configuration enables a study of the internal quality factor of the chain while the first one is more
suited to study quantitatively the Kerr effects occurring between different modes in the chain. The experimental dispersion curve
of this meta- material fits well the theoretical prediction. We measured the Self- and Cross Kerr effects by two-tone spectroscopy
measurements for the first 8 modes of the chain and compare them to theory. Secondly, I will show our recent results on the realization
of a fluxonium qubit. I will discuss spectroscopy measurements and measurements of the relaxation and decoherence time of this
qubit. At the end I will discuss future experiments with fluxonium type devices.
Figure 1: A fluxonium qubit fabricated at the Néel Institute Grenoble
Biography
Wiebke Guichard is a Professor at University Grenoble Alpes. During her PhD in the low temperature laboratory CRTBT/CNRS in Grenoble, she realized the first
phase-sensitive measurement of a ferromagnetic hybrid π-junction. Her Postdoc research at KTH in the group of David Haviland, dealt with Bloch oscillations
both in a single junction and in a Cooper pair transistor (CPT), coupled to a highly resistive environment consisting of SQUID arrays. Since September 2004, she
is a working in the Superconducting Quantum Circuit group in the Neel Institute in Grenoble together with Olivier Buisson and Nicolas Roch. She worked at the
beginning on a coupled qubit-circuit between a phase-qubit and a charge qubit. Since 2008, she is working on quantum dynamics in Josephson junction chains and
currently she is supervising a project on non-linear effects in Josephson junction chains.
Wiebke Guichard, J Laser Opt Photonics 2017, 4:3(Suppl)
DOI: 10.4172/2469-410X-C1-014