160 research outputs found
Two-photon path-entangled states in multi-mode waveguides
We experimentally show that two-photon path-entangled states can be
coherently manipulated by multi-mode interference in multi-mode waveguides. By
measuring the output two-photon spatial correlation function versus the phase
of the input state, we show that multi-mode waveguides perform as nearly-ideal
multi-port beam splitters at the quantum level, creating a large variety of
entangled and separable multi-path two-photon states.Comment: 4 pages, 4 figure
Radiative cascades in charged quantum dots
We measured, for the first time, two photon radiative cascades due to
sequential recombination of quantum dot confined electron hole pairs in the
presence of an additional spectator charge carrier. We identified direct, all
optical cascades involving spin blockaded intermediate states, and indirect
cascades, in which non radiative relaxation precedes the second recombination.
Our measurements provide also spin dephasing rates of confined carriers.Comment: 4 pages, 3 figure
Single-photon synchronization with a room-temperature atomic quantum memory
Efficient synchronization of single photons that are compatible with
narrowband atomic transitions is an outstanding challenge, which could prove
essential for photonic quantum information processing. Here we report on the
synchronization of independently-generated single photons using a
room-temperature atomic quantum memory. The photon source and the memory are
interconnected by fibers and employ the same ladder-level atomic scheme. We
store and retrieve the heralded single photons with end-to-end efficiency of
and final anti-bunching of . Our
synchronization process results in over tenfold increase in the photon-pair
coincidence rate, reaching a rate of more than detected synchronized
photon pairs per second. The indistinguishability of the synchronized photons
is verified by a Hong-Ou-Mandel interference measurement
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