Quantum logic gates based on off-resonant cavity-assisted interaction between three-level atoms and single photons

Chui‐Ping Yang, Shih‐I Chu

M Akbari, S N Andrianov, А. А. Калачев

Abstract A scheme for implementing quantum gates on the basis of a hybrid system that consists of flying photons and a stationary three-level atom interacting with each other in a microring resonator is developed. By employing the Schrieffer–Wolf transformation, it is shown that various two-qubit gates can be implemented under conditions of dispersive interaction without the need for orthogonal Λ structure of optical transitions. As a promising system for implementation, NV centers are considered.

Changyong Chen, Mang Feng, Xiaolong Zhang +1 more

We propose a potential scheme for carrying out two-qubit unconventional geometric logic gates on two identical three-level atoms in a cavity, strongly driven by a resonant classical field. Compared to a previous scheme [S. B. Zheng, Phys. Rev. A 70, 052320 (2004)] based on the large-detuning interaction of the two identical three-level atoms with the cavity mode, our scheme can, in principle, achieve a faster gating because of the resonant coupling of the atoms to the classical field. We present the two-qubit unconventional geometric phase gates in both an ideal cavity and a real cavity with decay. Discussions about the fidelity and the success probability of the proposed scheme as well as the experimental feasibility are made in detail.

Bastian Hacker, Stephan Welte, Gerhard Rempe +1 more

M. Khanbekyan, Dirk‐Gunnar Welsch

Stimulated Raman interaction of a classically pumped single three-level $Λ$-type atom in a resonator cavity featuring both radiative and unwanted losses is studied. It is shown that in the regime of stimulated adiabatic Raman passage the excited outgoing wave packet of the cavity-assisted electromagnetic field can be prepared in a one-photon Fock state with high efficiency. In this regime, the spatio-temporal shape of the wave packet does not depend on the interaction shape of the pump field, provided that the interaction of the atom with the pump is time-delayed with respect to the interaction of the atom with the cavity-assisted field. Therefore, the scheme can be used to generate a sequence of identical radiation pulses each of almost one-photon Fock state. It is further shown that the spatio-temporal shape of the outgoing wave packet can be manipulated by controlling the time of interaction between the atom and the cavity-assisted electromagnetic field.

Guo‐Zhu Song, Qian Liu, Jing Qiu +5 more