Microcavity controlled coupling of excitonic qubits

作者：Albert F; Sivalert**** K; Kasprzak J; Strauss M; Schneider C; Hofling S; Kamp M; Forchel A; Reitzenstein S; Muljarov E A; Langbein W^*

来源：Nature Communications, 2013, 4: 1747.

DOI：10.1038/ncomms2764

Controlled non-local energy and coherence transfer enables light harvesting in photosynthesis and non-local logical operations in quantum computing. This process is intuitively pictured by a pair of mechanical oscillators, coupled by a spring, allowing for a reversible exchange of excitation. On a microscopic level, the most relevant mechanism of coherent coupling of distant quantum bits-like trapped ions, superconducting qubits or excitons confined in semiconductor quantum dots-is coupling via the electromagnetic field. Here we demonstrate the controlled coherent coupling of spatially separated quantum dots via the photon mode of a solid state microresonator using the strong exciton-photon coupling regime. This is enabled by two-dimensional spectroscopy of the sample%26apos;s coherent response, a sensitive probe of the coherent coupling. The results are quantitatively understood in a rigorous description of the cavity-mediated coupling of the quantum dot excitons. This mechanism can be used, for instance in photonic crystal cavity networks, to enable a long-range, non-local coherent coupling.

• 出版日期2013-4