June 22, 2010
Controlling interaction of light and matter is a major advance toward large-scale quantum computing
CAMBRIDGE, Mass., - Raytheon Company's (NYSE: RTN) BBN Technologies has achieved a major advance in quantum information technology with the coupling of light and superconductors.
The achievement is described in a paper, "Direct Observation of Coherent Population Trapping in a Superconducting Artificial Atom," that was recently published in Physical Review Letters. Written by three Raytheon BBN physicists, William R. Kelly, Zachary Dutton, and Thomas A. Ohki, and colleagues John Schlafer and Bhaskar Mookerji, as well as two additional collaborators from the National Institute of Standards and Technology, the paper describes a physics breakthrough that author Zachary Dutton predicted in a paper he published in 2004.
Similar quantum interference effects have been seen with light and atoms in the past, but this is the first such observation with superconductors. Normally, superconducting artificial atoms absorb photons at a particular frequency. However, the authors have discovered that applying a second field at a different frequency can be used to prevent this absorption, making the artificial atom effectively transparent.
The discovery opens up a new possibility in the quest for efficient coupling of superconducting quantum bits, or qubits. "Superconducting artificial atoms offer fast and reliable processing, and light offers fast and reliable transmission over long distances," said Will Kelly, associate scientist, Raytheon BBN Technologies. "Combining light and superconducting artificial atoms offers the best of both and is a promising development for building a large-scale quantum computer."
Zachary Dutton, senior scientist, Raytheon BBN Technologies, said, "The next step is to demonstrate that we can slow light down, which would enable us to build a system that can store light, a vital piece for quantum computing."
Raytheon BBN Technologies President Tad Elmer added, "Controlling the interaction between light and matter is an extraordinary research achievement, and it's even more remarkable that it was done at a U.S. industrial lab."
Raytheon BBN Technologies is a wholly owned subsidiary of Raytheon Company.