Quantum metamaterials: Electromagnetic waves in a Josephson qubit line
Abstract
We consider the propagation of a classical electromagnetic wave through a transmission line, formed by identical superconducting charge qubits inside a superconducting resonator. Since the qubits can be in a coherent superposition of quantum states, we show that such a system demonstrates interesting effects, such as a “breathing” photonic crystal with an oscillating band gap and a “quantum Archimedean screw” that transports, at an arbitrary controlled velocity, Josephson plasma waves through a transmission line. The key ingredient of these effects is that the optical properties of the Josephson transmission line are controlled by the quantum coherent state of the qubits.
 Publication:

Physical Review B
 Pub Date:
 April 2008
 DOI:
 10.1103/PhysRevB.77.144507
 arXiv:
 arXiv:0709.1314
 Bibcode:
 2008PhRvB..77n4507R
 Keywords:

 74.78.Fk;
 74.50.+r;
 42.50.p;
 Multilayers superlattices heterostructures;
 Tunneling phenomena;
 point contacts weak links Josephson effects;
 Quantum optics;
 Condensed Matter  Superconductivity;
 Condensed Matter  Other Condensed Matter;
 Quantum Physics
 EPrint:
 References added