Phys. Status Solidi B 246, No. 5, 955–960 (2009) / DOI 10.1002/pssb.200881568 p s sb solidi status www.pss-b.com physica Quantum metamaterials: basic solid state physics Electromagnetic waves in Josephson qubit lines A. M. Zagoskin1,2,3*, A. L. Rakhmanov1,4, Sergey Savel’ev1,2, and Franco Nori1,5 1 Frontier Research System, The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama, 351-0198, Japan 2 Department of Physics, Loughborough University, Loughborough LE11 3TU, United Kingdom 3 Physics and Astronomy Department, The University of British Columbia, Vancouver, B.C., V6T 1Z1, Canada 4 Institute for Theoretical and Applied Electrodynamics RAS, 125412 Moscow, Russia 5 Department of Physics, Center for Theoretical Physics, Applied Physics Program, Center for the Study of Complex Systems, University of Michigan, Ann Arbor, MI 48109-1040, USA Received 15 October 2008, revised 4 February 2009, accepted 4 February 2009 Published online 3 April 2009 PACS 03.67.–a, 41.20.Jb, 82.25.Cp ∗ Corresponding author: e-mail
[email protected] We consider the propagation of a classical electromagnetic oscillating bandgap. Similar behaviour is expected from a wave through a transmission line, formed by identical super- transmission line formed by flux qubits. The key ingredient conducting charge qubits inside a superconducting resonator. of these effects is that the optical properties of the Josephson Since the qubits can be in a coherent superposition of quan- transmission line are controlled by the quantum coherent state tum states, we show that such a system demonstrates interest- of the qubits. ing new effects, such as a “breathing” photonic crystal with an © 2009 WILEY-VCH Verlag GmbH & Co.