QDev Seminar: Steven M. Girvin
Yale Quantum Institute
Quantum Information Processing with Microwave Photons
This talk will describe recent theoretical and experimental progress towards creation of a modular architecture for quantum information processing in which the qubits are not material objects but rather superposition states of microwave photons stored in cavities with millisecond lifetimes. The Josephson junction elements used as qubits in more traditional architectures are used here only as ancillae to provide universal control over the non-classical photon states. Recent experimental progress in execution of new gate operations that entangle photons in separate cavities will be described. These gates [SWAP, C-SWAP (Fredkin), exponential-SWAP] have the remarkable feature that they are universal in the sense that they do not depend on the particular encoding used to store quantum information in the photons. The modular approach based on photon states is also highly advantageous for quantum error correction and fault tolerance.