Quantum dot single-photon source

<p>A quantum dot single-photon source is based on a single <a href="/facts/Quantum_dot/K5Ytv8Yw">quantum dot</a> placed in an <a href="/facts/Optical_cavity/BITPG3ga">optical cavity</a>. It is an on-demand single-photon source. A laser pulse can excite a pair of carriers known as an <a href="/facts/Exciton/aFIBtIqQ">exciton</a> in the quantum dot. The decay of a single exciton due to <a href="/facts/Spontaneous_emission/kWWfqQ2V">spontaneous emission</a> leads to the emission of a single photon. Due to interactions between excitons, the emission when the quantum dot contains a single exciton is energetically distinct from that when the quantum dot contains more than one exciton. Therefore, a single exciton can be deterministically created by a laser pulse and the quantum dot becomes a <a href="/facts/Nonclassical_light/KHTAJx5e">nonclassical light</a> source that emits photons one by one and thus shows <a href="/facts/Photon_antibunching/FWGyBnHY">photon antibunching</a>. The emission of single photons can be proven by measuring the <a href="/facts/Degree_of_coherence/Wt05M2Rs">second order intensity correlation function</a>. The <a href="/facts/Spontaneous_emission/kWWfqQ2V">spontaneous emission</a> rate of the emitted <a href="/facts/Photon/mFNhAEzA">photons</a> can be enhanced by integrating the quantum dot in an <a href="/facts/Optical_cavity/BITPG3ga">optical cavity</a>. Additionally, the cavity leads to emission in a well-defined optical mode increasing the efficiency of the photon source.
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Quantum dot single-photon source open-in-new

Quantum dot single-photon source