Downconversion quantum interface for a single quantum dot spin and 1550-nm single-photon channel

Abstract

Abstract:Long-distance quantum communication networks require appropriate interfaces between matter qubit-based nodes and low-loss photonic quantum channels. We implement a downconversion quantum interface, where the single photons emitted from a semiconductor quantum dot at 910 nm are downconverted to 1560 nm using a fiber-coupled periodically poled lithium niobate waveguide and a 2.2-µm pulsed pump laser. The single-photon character of the quantum dot emission is preserved during the downconversion process: we measure a cross-correlation g (2) (τ = 0) = 0.17 using resonant excitation of the quantum dot. We show that the downconversion interface is fully compatible with coherent optical control of the quantum dot electron spin through the observation of Rabi oscillations in the downconverted photon counts. These results represent a critical step towards a long-distance hybrid quantum network in which subsystems operating at different wavelengths are connected through quantum frequency conversion devices and 1.5-µm quantum channels. References and links1. H. J. Kimble, "The quantum internet," Nature (London) 453, 1023-1030 (2008 Yamamoto, "Quantum-dot spin-photon entanglement via frequency downconversion to telecom wavelength," Nature (London) 491, 421-425 (2012). 34. H. Takesue, "Erasing distinguishability using quantum frequency up-conversion," Phys. Rev. Lett. 101, 173901-4 (2008).

Exciton and biexciton dynamics in single self-assembled InAs/InGaAlAs/InP quantum dash emitting near 1.55 μm

“…18 Since the third telecommunication window centered around 1.55 lm guarantees the lowest transmission losses and highest transmission rates, a true single quantum photon emitter at that wavelength is highly sought for. 19 Among already demonstrated solutions towards achieving single quantum emitter at 1.55 lm including PbS nanocrystals, 20 metamorphic InAs/(In,Ga)As self-assembled QDs, 21 InAsP/InP QDs, 22 InAs/InP QDs, 18,[23][24][25][26] and combined techniques using standard InAs/GaAs QDs and frequency down conversion, 27 the idea of utilizing the InAs/InP(001) QDashes 28 is still original and competitive.…”

Ultrafast optical control of individual electron and hole spin qubits: entanglement between a single quantum dot electron spin and a downconverted 1560-nm single photon

“…By using a classical, few-ps lightpulse at 910 nm, the cross-correlation can be measured with the 2.2 μm mixing field, by monitoring the 1560 nm count rates. This cross-correlation can be shown to form a bound for the single-photon level timing resolution [1,2]. We obtain a resolution of 8 ps or better.…”

“…2 b)). Those permit optical access to the spin states, and all-optical manipulation of the spin-state, and spin-photon entanglement [1,2].…”

“…The technique used consists of frequency-downconverting the single-photons from the quantum dot (emission wavelength: 910 nm; photon flux: 200,000 cps @ 20% QE for a 76 MHz repetition rate) in a periodically poled lithiumniobate waveguide device [1,6]. Such waveguide devices strongly enhance the χ (2) -nonlinearity present in lithiumniobate by concentrating the fields and avoiding diffraction effects, while the periodic poling allows for quasiphasematching, again enhancing the non-linearity.…”

Complete tomography of a high-fidelity solid-state entangled spin–photon qubit pair

“…Conversely, the equivalent frequency difference between the H-and V-polarized branches of the spontaneous emission decay, do, can result in frequency-which-path information leaking out to the environment 21,19 . By mixing a short gating pulse with the single photon in a nonlinear crystal (a periodically poled lithium niobate (PPLN) waveguide 21,27 , see Fig. 1c), we can postselect for the photon's exact arrival time, with sub-8 ps timing resolution and with negligible background noise.…”