Superconducting resonators as beam splitters for linear-optics quantum computation.

We propose and analyze a technique for producing a beam-splitting quantum gate between two modes of a ring-resonator superconducting cavity. The cavity has two integrated superconducting quantum interference devices (SQUIDs) that are modulated by applying an external magnetic field. The gate is accomplished by applying a radio frequency pulse to one of the SQUIDs at the difference of the two mode frequencies. Departures from perfect beam splitting only arise from corrections to the rotating wave approximation; an exact calculation gives a fidelity of >0.9992. Our construction completes the toolkit for linear-optics quantum computing in circuit quantum electrodynamics.

[1]  L. DiCarlo,et al.  Demonstration of two-qubit algorithms with a superconducting quantum processor , 2009, Nature.

[2]  M. S. Zubairy,et al.  Quantum optics: Frontmatter , 1997 .

[3]  S. Girvin,et al.  Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics , 2004, Nature.

[4]  G. Milburn,et al.  Linear optical quantum computing with photonic qubits , 2005, quant-ph/0512071.

[5]  Driver-phase-correlated fluctuations in the rotation of a strongly driven quantum bit , 2004 .

[6]  R. Collin.  Foundations for microwave engineering , 1966 .

[7]  D. D. Awschalom,et al.  Gigahertz Dynamics of a Strongly Driven Single Quantum Spin , 2009, Science.

[8]  David P. DiVincenzo,et al.  Multilevel quantum description of decoherence in superconducting qubits , 2004 .

[9]  Milburn,et al.  Quantum optical Fredkin gate. , 1989, Physical review letters.

[10]  Dutta,et al.  Quantum-noise matrix for multimode systems: U(n) invariance, squeezing, and normal forms. , 1994, Physical review. A, Atomic, molecular, and optical physics.

[11]  A. Siegert,et al.  Magnetic Resonance for Nonrotating Fields , 1940 .

[12]  E. Knill,et al.  A scheme for efficient quantum computation with linear optics , 2001, Nature.

[13]  M. Mariantoni,et al.  Two-resonator circuit quantum electrodynamics : A superconducting quantum switch , 2007, 0712.2522.

[14]  Hongguo Xu,et al.  An SVD-like matrix decomposition and its applications , 2003 .

[15]  Erik Lucero,et al.  Synthesizing arbitrary quantum states in a superconducting resonator , 2009, Nature.

[16]  Dutta,et al.  Two-mode quantum systems: Invariant classification of squeezing transformations and squeezed states. , 1994, Physical review. A, Atomic, molecular, and optical physics.