A solid state source of photon triplets based on quantum dot molecules

Abstract

Producing advanced quantum states of light is a priority in quantum information technologies. In this context, experimental realizations of multipartite photon states would enable improved tests of the foundations of quantum mechanics as well as implementations of complex quantum optical networks and protocols. It is favourable to directly generate these states using solid state systems, for simpler handling and the promise of reversible transfer of quantum information between stationary and flying qubits. Here we use the ground states of two optically active coupled quantum dots to directly produce photon triplets. The formation of a triexciton in these ground states leads to a triple cascade recombination and sequential emission of three photons with strong correlations. We record 65.62 photon triplets per minute under continuous-wave pumping, surpassing rates of earlier reported sources. Our structure and data pave the way towards implementing multipartite photon entanglement and multi-qubit readout schemes in solid state devices.

Multiphoton nonclassical light from clusters of single-photon emitters

“…Realization of such processes remains a challenge, although there are several experimental attempts to generate photon triplets through the third-order interaction in nonlinear crystals [2], waveguides [3], and fibers [4]. Generation of photon triplets from solid-state emitters, such as 'quantum dot molecules' [5] is another option. Finally, multiphoton states can be produced by heralding and interference applied to sufficiently bright twin beams, obtained through high-gain parametric down-conversion.…”

Design of Quantum Dot-Nanowire Single-Photon Sources that are Immune to Thermomechanical Decoherence

“…Even at cryogenic temperature, the thermal excitation of a single mechanical mode can then have a sizable influence on the QD optical linewidth. This was demonstrated very recently on a QD embedded in a nanowire antenna [19], a system widely employed to realize bright sources of quantum light [20][21][22][23][24][25][26]. These initial experimental results unveil a previously overlooked QD decoherence channel.…”

Theory and experiments of coherent photon coupling in semiconductor nanowire waveguides with quantum dot molecules

“…Experimental spectra for selected QD separations using the diameter-controlled approach are shown in Fig. 13 4 . We observe a clear red-shift in the emission energies of the dots with decreasing R (e.g.…”