Coupled quantum electrodynamics in photonic crystal cavities towards controlled phase gate operations

Y-F Xiao,Y-L Chen,X Yang,C W Wong,J Gao,X-B Zou,G-C Guo,J F Mcmillan,Z-F Han

doi:10.1088/1367-2630/10/12/123013

Y-F Xiao, Y-L Chen + Show 7 more

Open Access

https://doi.org/10.1088/1367-2630/10/12/123013

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Abstract

In this paper, a scalable photonic crystal cavity array, in which single embedded quantum dots (QDs) are coherently interacting, is studied theoretically. Firstly, we examine the spectral character and optical delay brought about by the coupled cavities interacting with single QDs, in an optical analogue to electromagnetically induced transparency. Secondly, we then examine the usability of this coupled QD–cavity system for quantum phase gate operation and our numerical examples suggest that a two-qubit system with fidelity above 0.99 and photon loss below 0.04 is possible.

Highlights

Spectral character of coupled quantum dots (QDs)–cavity arraysTo examine the physical essence, we need to first examine the spectral character of the coupled cavity–QD system
(5) 1 m jth quantum dots (QDs)-cavity and vacuum Rabi splitting [20, 21], transfer of single photons between two cavities [22], deterministic positioning of a cavity mode with respect to a QD [23], and controlling cavity reflectivity with a single QD [24]
We study the possibility of quantum phase gate operation of the QDs based on this transport character

Summary

Spectral character of coupled QD–cavity arrays

To examine the physical essence, we need to first examine the spectral character of the coupled cavity–QD system. The reflection and transmission coefficients are defined as rN1 (ω) ≡ ao(1u)t (ω) /ai(n1) (ω) and tN1 (ω) ≡ bo(Nut) (ω) /ai(n1) (ω). (b) Numerical 3D FDTD simulations of the optical analogue of EIT in two coupled cavities (θ = 0) for detunings 1.14 (red; εcavities = 0.135), 1.26 (blue; εcavities = 0.160) and 1.49 (green; εcavities = 0.185). The arrows denote the EIT peak transmissions. The dashed gray lines denote the two detuned individual resonances for the case of s1 = 0.05a. The black curve is for a single cavity transmission for reference. (c) Example Ex -field distribution of coupled empty photonic crystal cavities.

Phase shift and photon storage

Quantum phase gate operation

Gate fidelity and photon loss

Conclusion