Temporally and spectrally multiplexed single photon source using quantum feedback control for scalable photonic quantum technologies

Abstract

Current proposals for scalable photonic quantum technologies require on-demand sources of indistinguishable single photons with very high efficiency. Even with recent progress in the field there is still a significant gap between the requirements and state of the art performance. Here, we propose an on-chip source of time-multiplexed, heralded photons. Using quantum feedback control on a photon storage cavity with an optimized driving protocol, we estimate an on-demand efficiency of 99% and unheralded loss of order 1%, assuming high efficiency detectors and intrinsic cavity quality factors of order 10 8 . We further explain how temporal-and spectral-multiplexing can be used in parallel to significantly reduce device requirements if single photon frequency conversion is possible with efficiency in the same range of 99%.

Unidirectional frequency conversion in microring resonators for on-chip frequency-multiplexed single-photon sources

“…Electronic feedback control at these short timescales remains to be demonstrated, but since many quantum information processing tasks rely on it, we are optimistic that the field will progress sufficiently. For an analysis of the full system efficiency including latency in the quantum feedback as well as detector efficiency, we refer to [21]. Importantly, we note that extraction of the created signal photon from the ring is included in the frequency conversion efficiency here, whereas the loss associated with this process was not treated in [21].…”

“…For an analysis of the full system efficiency including latency in the quantum feedback as well as detector efficiency, we refer to [21]. Importantly, we note that extraction of the created signal photon from the ring is included in the frequency conversion efficiency here, whereas the loss associated with this process was not treated in [21]. We consider our proposal to be a very promising route to on-chip multiplexed single-photon sources for near-term implementation.…”

“…A major advantage of our proposal is the elimination of spatial switches used in e.g. [21] by converting signal photons to a common output mode, out w , which is strongly coupled to the bus waveguide. It is even possible to shape the wave packet of the output photons by tailoring the temporal shape of the BS-FWM pumps, which we show insection 3.3.…”

Spatially multiplexed single-photon sources based on incomplete binary-tree multiplexers

“…The inherent probabilistic nature of the photon pair generation in these nonlinear sources results in the occasional occurrence of multiphoton events in the pair generation. This detrimental effect can be reduced by various multiplexing techniques such as spatial multiplexing [8][9][10][11][12][13][14] and time multiplexing [15][16][17][18][19][20][21][22][23][24][25][26][27] where heralded photons generated in a set of multiplexed units realized in space or in time are rerouted to a single output mode by a switching system. In multiplexed SPSs, the multi-photon noise can be suppressed by keeping the mean photon number of the generated photon pairs low in a multiplexed unit, while the high probability of successful heralding in the whole system can be guaranteed by the use of several multiplexed units.…”

Bright photon-pair source based on a silicon dual-Mach-Zehnder microring

“…This design has since been used to tune the bandwidths of ring-resonatorbased filters [5,6] and as an ingenious sensor [7]. Recently, several studies [8][9][10] have also adopted this design to adjust the quality factors of the interacting beams in SFWM to either concentrate the photon pairs, resulting in emission from one of the ports of an add-drop structure, or enhance the photons' spectral purity. Herein, we use a dual-AMZI-coupled resonator to control the coupling conditions of the pump, signal, and idler photons independently, conducting experiments to approach the optimal coupling conditions by fabricating a series of dual-AMZI-coupled resonators with different coupling parameters.…”