Tunable coupling of transmission-line microwave resonators mediated by an rf SQUID

Friedrich Wulschner; Jan Goetz; Fabian R Koessel; Elisabeth Hoffmann; Alexander Baust; Peter Eder; Michael Fischer; Max Haeberlein; Manuel J Schwarz; Matthias Pernpeintner; Edwar Xie; Ling Zhong; Christoph W Zollitsch; Borja Peropadre; Juan-Jose Garcia Ripoll; Enrique Solano; Kirill G Fedorov; Edwin P Menzel; Frank Deppe; Achim Marx; Rudolf Gross

doi:10.1140/epjqt/s40507-016-0048-2

EPJ

Tunable coupling of transmission-line microwave resonators mediated by an rf SQUID

Friedrich Wulschner¹^,2, Jan Goetz¹^,2, Fabian R Koessel¹^,2, Elisabeth Hoffmann¹^,2, Alexander Baust¹^,2^,3, Peter Eder¹^,2^,3, Michael Fischer¹^,2^,3, Max Haeberlein¹^,2, Manuel J Schwarz¹^,2^,3, Matthias Pernpeintner¹^,2^,3, Edwar Xie¹^,2^,3, Ling Zhong¹^,2^,3, Christoph W Zollitsch¹^,2, Borja Peropadre⁴, Juan-Jose Garcia Ripoll⁵, Enrique Solano²^,6^,7, Kirill G Fedorov¹^,2, Edwin P Menzel¹^,2, Frank Deppe¹^,2^,3, Achim Marx¹ and Rudolf Gross¹^,2^,3^*

¹ Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, Garching, 85748, Germany
² Physik-Department, Technische Universität München, Garching, 85748, Germany
³ Nanosystems Initiative Munich (NIM), Schellingstraße 4, München, 80799, Germany
⁴ Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Cambridge, Massachusetts, 02138, United States
⁵ Instituto de Física Fundamental IFF-CSIC, Calle Serrano 113b, Madrid, 28006, Spain
⁶ Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, Bilbao, 48080, Spain
⁷ IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, Bilbao, 48013, Spain

Received: 14 March 2016
Accepted: 8 July 2016
Published online: 28 July 2016

Abstract

We realize tunable coupling between two superconducting transmission line resonators. The coupling is mediated by a non-hysteretic rf SQUID acting as a flux-tunable mutual inductance between the resonators. We present a spectroscopic characterization of the device. In particular, we observe couplings $g/2\pi$ ranging between −320 MHz and 37 MHz. In the case of $g \simeq 0$ , the microwave power cross transmission between the two resonators is reduced by almost four orders of magnitude as compared to the case where the coupling is switched on.

15th European Conference on Atoms Molecules and Photons (ECAMP)
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EPJ

Tunable coupling of transmission-line microwave resonators mediated by an rf SQUID

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