title: Hybrid Toffoli gate on photons and quantum spins.
abstract: Quantum computation offers potential advantages in solving a number of interesting and difficult problems. Several controlled logic gates, the elemental building blocks of quantum computer, have been realized with various physical systems. A general technique was recently proposed that significantly reduces the realization complexity of multiple-control logic gates by harnessing multi-level information carriers. We present implementations of a key quantum circuit: the three-qubit Toffoli gate. By exploring the optical selection rules of one-sided optical microcavities, a Toffoli gate may be realized on all combinations of photon and quantum spins in the QD-cavity. The three general controlled-NOT gates are involved using an auxiliary photon with two degrees of freedom. Our results show that photons and quantum spins may be used alternatively in quantum information processing.
authors.affiliation: Information Security and National Computing Grid Laboratory, Southwest Jiaotong University, Chengdu 610031, China.
authors.forename: Ming-Xing
authors.initials: MX
authors.lastname: Luo
authors.affiliation: School of Mathematics and Statistics, Henan University, Kaifeng 475004, China.
authors.forename: Song-Ya
authors.initials: SY
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, China.
authors.forename: Xiu-Bo
authors.initials: XB
authors.lastname: Chen
authors.affiliation: School of Electronic Engineering, Dublin City University, Dublin 9, Ireland.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Wang