Optical multiqubit gate operations on an excitation-blockaded atomic quantum register

Quantum optical Fredkin gate.

An all-optical quantum gate in a semiconductor quantum dot.

We report coherent optical control of a biexciton (two electron-hole pairs), confined in a single quantum dot, that shows coherent oscillations similar to the excited-state Rabi flopping in an isolated atom. The pulse control of the biexciton dynamics, combined with previously demonstrated control of the single-exciton Rabi rotation, serves as the physical basis for a two-bit conditional quantu...

Quantum controlled-phase-flip gate between a flying optical photon and a Rydberg atomic ensemble

Quantum controlled-phase-flip (CPF) gate between a flying photon qubit and a stationary atomic qubit could allow the linking of distant computational nodes in a quantum network. Here we present a scheme to realize quantum CPF gate between a flying optical photon and an atomic ensemble based on cavity input-output process and Rydberg blockade. When a flying single-photon pulse is reflected off t...

Self-stabilized quantum optical Fredkin gate.

The quantum optical Fredkin gate is an indispensable resource for networkable quantum applications. Its performance in practical implementations, however, is limited fundamentally by the inherent quantum fluctuations of the pump waves. We demonstrate a method to overcome this drawback by exploiting stimulated Raman scattering in fiber-based implementations. Using a Sagnac fiber-loop switch as a...

Cavity-mediated long-range interaction for fast multiqubit quantum logic operations

Kishore T. Kapale, ∗ Girish S. Agarwal, and Marlan O. Scully 4 Quantum Computing Technologies Group, Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 126-347, 4800 Oak Grove Drive, Pasadena, California 91109-8099 Dept. of Physics, Oklahoma State University, Stillwater, Oklahoma 74078-3072 Inst. for Quantum Studies & Dept. of Physics, Texas A&M University, College Station...