61 research outputs found
Cesiumâvaporâbased delay of single photons emitted by deterministically fabricated quantum dot microlenses
Quantum light sources are key building blocks of photonic quantum technologies. For many applications, it is of interest to control the arrival time of single photons emitted by such quantum devices, or even to store single photons in quantum memories. In situ electron beam lithography is applied to realize InGaAs quantum dot (QD)âbased singleâphoton sources, which are interfaced with cesium (Cs) vapor to control the time delay of emitted photons. Via numerical simulations of the lightâmatter interaction in realistic QDâCsâvapor configurations, the influence of the vapor temperature and spectral QDâatom detuning is explored to maximize the achievable delay in experimental studies. As a result, this hybrid quantum system allows to trigger the emission of single photons with a linewidth as low as 1.54 GHz even under nonâresonant optical excitation and to delay the emission pulses by up to (15.71 ± 0.01) ns for an effective cell length of 150 mm. This work can pave the way for scalable quantum systems relying on a wellâcontrolled delay of single photons on a time scale of up to a few tens of nanoseconds.BMBF, 03V0630TIB, Entwicklung einer Halbleiterbasierten Einzelphotonenquelle fĂŒr die QuanteninformationstechnologieBMBF, 13N14876, Quantenkommunikations-Systeme auf Basis von Einzelphotonenquellen (QuSecure)DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeTU Berlin, Open-Access-Mittel - 201
Resonance fluorescence of a site-controlled quantum dot realized by the buried-stressor growth technique
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 110, 111101 (2017) and may be found at https://doi.org/10.1063/1.4978428.Site-controlled growth of semiconductor quantum dots (QDs) represents a major advancement to achieve scalable quantum technology platforms. One immediate benefit is the deterministic integration of quantum emitters into optical microcavities. However, site-controlled growth of QDs is usually achieved at the cost of reduced optical quality. Here, we show that the buried-stressor growth technique enables the realization of high-quality site-controlled QDs with attractive optical and quantum optical properties. This is evidenced by performing excitation power dependent resonance fluorescence experiments at cryogenic temperatures showing QD emission linewidths down to 10âÎŒeV. Resonant excitation leads to the observation of the Mollow triplet under CW excitation and enables coherent state preparation under pulsed excitation. Under resonant Ï-pulse excitation we observe clean single-photon emission associated with g(2)(0)â=â0.12 limited by non-ideal laser suppression.EC/FP7/615613/EU/External Quantum Control of Photonic Semiconductor Nanostructures/EXQUISIT
Operating single quantum emitters with a compact Stirling cryocooler
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Review of Scientific Instruments 86, 013113 (2015) and may be found at https://doi.org/10.1063/1.4906548.The development of an easy-to-operate light source emitting single photons has become a major driving force in the emerging field of quantum information technology. Here, we report on the application of a compact and user-friendly Stirling cryocooler in the field of nanophotonics. The Stirling cryocooler is used to operate a single quantum emitter constituted of a semiconductor quantum dot (QD) at a base temperature below 30 K. Proper vibration decoupling of the cryocooler and its surrounding enables free-space micro-photoluminescence spectroscopy to identify and analyze different charge-carrier states within a single quantum dot. As an exemplary application in quantum optics, we perform a Hanbury-Brown and Twiss experiment demonstrating a strong suppression of multi-photon emission events with g(2)(0) < 0.04 from this Stirling-cooled single quantum emitter under continuous wave excitation. Comparative experiments performed on the same quantum dot in a liquid helium (LHe)-flow cryostat show almost identical values of g(2)(0) for both configurations at a given temperature. The results of this proof of principle experiment demonstrate that low-vibration Stirling cryocoolers that have so far been considered exotic to the field of nanophotonics are an attractive alternative to expensive closed-cycle cryostats or LHe-flow cryostats, which could pave the way for the development of high-quality table-top non-classical light sources.BMBF, 03V0630, Entwicklung einer Halbleiterbasierten Einzelphotonenquelle fĂŒr die Quanteninformationstechnologie (QSOURCE)DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, Bauelement
Two-photon interference from remote deterministic quantum dot microlenses
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 110, 011104 (2017) and may be found at https://doi.org/10.1063/1.4973504.We report on two-photon interference (TPI) experiments using remote deterministic single-photon sources. Employing 3D in-situ electron-beam lithography, we fabricate quantum-light sources at specific target wavelengths by integrating pre-selected semiconductor quantum dots within monolithic microlenses. The individual single-photon sources show TPI visibilities of 49% and 22%, respectively, under pulsed p-shell excitation at 80âMHz. For the mutual TPI of the remote sources, we observe an uncorrected visibility of 29%, in quantitative agreement with the pure dephasing of the individual sources. Due to its efficient photon extraction within a broad spectral range (>20ânm), our microlens-based approach is predestinated for future entanglement swapping experiments utilizing entangled photon pairs emitted by distant biexciton-exciton radiative cascades.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeEC/FP7/615613/EU/External Quantum Control of Photonic Semiconductor Nanostructures/EXQUISIT
Deterministic integration of quantum dots into on-chip multi-mode interference beamsplitters using in-situ electron beam lithography
The development of multi-node quantum optical circuits has attracted great
attention in recent years. In particular, interfacing quantum-light sources,
gates and detectors on a single chip is highly desirable for the realization of
large networks. In this context, fabrication techniques that enable the
deterministic integration of pre-selected quantum-light emitters into
nanophotonic elements play a key role when moving forward to circuits
containing multiple emitters. Here, we present the deterministic integration of
an InAs quantum dot into a 50/50 multi-mode interference beamsplitter via
in-situ electron beam lithography. We demonstrate the combined emitter-gate
interface functionality by measuring triggered single-photon emission on-chip
with . Due to its high patterning resolution as well
as spectral and spatial control, in-situ electron beam lithography allows for
integration of pre-selected quantum emitters into complex photonic systems.
Being a scalable single-step approach, it paves the way towards multi-node,
fully integrated quantum photonic chips.Comment: 20 pages, 5 figure
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