scholarly journals Superior properties in room-temperature colloidal-dot quantum emitters revealed by ultralow-dark-count detections of temporally-purified single photons

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Toshiyuki Ihara ◽  
Shigehito Miki ◽  
Toshiki Yamada ◽  
Takahiro Kaji ◽  
Akira Otomo ◽  
...  
Keyword(s):  
Room Temperature ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Photon Emission ◽  
Light Sources ◽  
Single Photons ◽  
Dark Count ◽  
Photon Detectors ◽  
High Quality ◽  
Quantum Emitters

Abstract The realization of high-quality quantum emitters that can operate at room temperature is important for accelerating the application of quantum technologies, such as quantum communication, quantum information processing, and quantum metrology. In this work, we study the photon-antibunching properties on room-temperature emission from individual colloidal quantum dots (CQDs) using superconducting-nanowire single-photon detectors and temporal filtering of the photoluminescence decay curve. We find that high single-photon purities and high photon-generation rates can be simultaneously achieved by removing the signals originating from the sequential two-photon emission of biexcitons created by multiple excitation pulses. We successfully demonstrate that the ultrahigh performance of the room-temperature single-photon sources showing g(2)(0) ≪ 10−2 can be confirmed by the ultralow-dark-count detection of the temporally purified single photons. These findings provide strong evidence for the attractiveness of CQDs as candidates for high-quality room-temperature quantum light sources.

scholarly journals Indistinguishable Photons from a Single Molecule under Pulsed Excitation

2021 ◽  
Vol 255 ◽  
pp. 06002
Author(s):  
Pietro Lombardi ◽  
Maja Colautti ◽  
Rocco Duquennoy ◽  
Ghulam Murtaza ◽  
Prosenjit Majumder ◽  
...  
Keyword(s):  
Single Molecule ◽  
Single Photon ◽  
Low Cost ◽  
Photon Emission ◽  
Light Sources ◽  
Single Photons ◽  
Quantum Communications ◽  
Ideal Quantum ◽  
On Chip ◽  
Key Resources

Quantum light sources are crucial for the future of quantum photonic technologies and, among them, single photons on-demand are key resources in quantum communications and information processing. Ideal quantum emitters providing indistinguishable photons in a clocked manner, negligible decoherence and spectral diffusion, and with potential for scalability are today still a major challenge. We report on photostable and indistinguishable single photon emission from dibenzoterrylene molecules isolated in anthracene nanocrystals (DBT:Ac NCs) at 3K. The visibility of two-photon interference is preserved even when they are separated more than thirty times the excited-state lifetime, or ten fluorescence cycles. One of the advantages of organic molecules is the low-cost mass production of nominally identical emitters, that also allow for on-chip integration. These aspects combined with high spectral stability and coherence make them promising for applications and future quantum technologies.

scholarly journals Room-temperature generation of heralded single photons on silicon chip with switchable orbital angular momentum

2022 ◽  
Author(s):  
Shan Zhang ◽  
Xue Feng ◽  
Wei Zhang ◽  
Kaiyu Cui ◽  
Fang Liu ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Room Temperature ◽  
Quantum Information Processing ◽  
Single Photon ◽  
High Dimensional ◽  
Single Photons ◽  
Single Photon Source ◽  
Material Systems ◽  
Photon Source

Abstract In quantum optics, orbital angular momentum (OAM) is very promising to achieve high-dimensional quantum states due to the nature of infinite and discrete eigenvalues, which is quantized by the topological charge of l. Here, a heralded single-photon source with switchable OAM modes is proposed and demonstrated on silicon chip. At room-temperature, the heralded single photons with 11 OAM modes (l=2~6, -6~-1) have been successfully generated and switched through thermo-optical effect. We believe that such an integrated quantum source with multiple OAM modes and operating at room-temperature would provide a practical platform for high-dimensional quantum information processing. Moreover, our proposed architecture can also be extended to other material systems to further improve the performance of OAM quantum source.

scholarly journals Photon counting statistics with imperfect detectors

2021 ◽  
Vol 2086 (1) ◽  
pp. 012096
Author(s):  
Aleksei Reutov ◽  
Denis Sych
Keyword(s):  
Continuous Wave ◽  
Single Photon ◽  
Functional Dependence ◽  
Photon Counting ◽  
Light Sources ◽  
Photon Detectors ◽  
Quantum Properties ◽  
Single Photon Detectors ◽  
The Mean ◽  
Counting Statistics

Abstract Measurement of photon statistics is an important tool for the verification of quantum properties of light. Due to the various imperfections of real single photon detectors, the observed statistics of photon counts deviates from the underlying statistics of photons. Here we analyze statistical properties of coherent states, and investigate a connection between Poissonian distribution of photons and sub-Poissonian distribution of photon counts due to the detector dead-time corrections. We derive a functional dependence between the mean number of photons and the mean number of photon counts, as well as connection between higher-order statistical moments, for the pulsed or continuous wave coherent light sources, and confirm the results by numerical simulations.

scholarly journals Chaotic Quantum Key Distribution

Cryptography ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 24
Author(s):  
Noah Cowper ◽  
Harry Shaw ◽  
David Thayer
Keyword(s):  
Quantum Computing ◽  
Quantum Key Distribution ◽  
Single Photon ◽  
Photon Emission ◽  
Key Distribution ◽  
Maximum Amount ◽  
Single Photons ◽  
Single Photon Emission ◽  
Amount Of Information ◽  
Communication Scheme

The ability to send information securely is a vital aspect of today’s society, and with the developments in quantum computing, new ways to communicate have to be researched. We explored a novel application of quantum key distribution (QKD) and synchronized chaos which was utilized to mask a transmitted message. This communication scheme is not hampered by the ability to send single photons and consequently is not vulnerable to number splitting attacks like other QKD schemes that rely on single photon emission. This was shown by an eavesdropper gaining a maximum amount of information on the key during the first setup and listening to the key reconciliation to gain more information. We proved that there is a maximum amount of information an eavesdropper can gain during the communication, and this is insufficient to decode the message.

scholarly journals Optical Chirality and Single-Photon Isolation

2020 ◽  
Author(s):  
Lei Tang ◽  
Keyu Xia
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Kerr Nonlinearity ◽  
Single Photons ◽  
Optical Isolation ◽  
Optical Chirality ◽  
Magneto Optical Effect ◽  
Quantum Optical

Optical isolation is important for protecting a laser from damage due to the detrimental back reflection of light. It typically relies on breaking Lorentz reciprocity and normally is achieved via the Faraday magneto-optical effect, requiring a strong external magnetic field. Single-photon isolation, the quantum counterpart of optical isolation, is the key functional component in quantum information processing, but its realization is challenging. In this chapter, we present all-optical schemes for isolating the backscattering from single photons. In the first scheme, we show the single-photon isolation can be realized by using a chiral quantum optical system, in which a quantum emitter asymmetrically couples to nanowaveguide modes or whispering-gallery modes with high optical chirality. Secondly, we propose a chiral optical Kerr nonlinearity to bypass the so-called dynamical reciprocity in nonlinear optics and then achieve room-temperature photon isolation with low insertion loss. The concepts we present may pave the way for quantum information processing in an unconventional way.

scholarly journals Integration of Single-Photon Emitters in 2D Materials with Plasmonic Waveguides at Room Temperature

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1663
Author(s):  
Kwang-Yong Jeong ◽  
Seong Won Lee ◽  
Jae-Hyuck Choi ◽  
Jae-Pil So ◽  
Hong-Gyu Park
Keyword(s):  
Integrated Circuits ◽  
Room Temperature ◽  
Single Photon ◽  
Hexagonal Boron Nitride ◽  
Photon Emission ◽  
Plasmonic Waveguide ◽  
Practical Implementation ◽  
Plasmonic Waveguides ◽  
Time Resolved ◽  
Ag Nanowire

Efficient integration of a single-photon emitter with an optical waveguide is essential for quantum integrated circuits. In this study, we integrated a single-photon emitter in a hexagonal boron nitride (h-BN) flake with a Ag plasmonic waveguide and measured its optical properties at room temperature. First, we performed numerical simulations to calculate the efficiency of light coupling from the emitter to the Ag plasmonic waveguide, depending on the position and polarization of the emitter. In the experiment, we placed a Ag nanowire, which acted as the plasmonic waveguide, near the defect of the h-BN, which acted as the single-photon emitter. The position and direction of the nanowire were precisely controlled using a stamping method. Our time-resolved photoluminescence measurement showed that the single-photon emission from the h-BN flake was enhanced to almost twice the intensity as a result of the coupling with the Ag nanowire. We expect these results to pave the way for the practical implementation of on-chip nanoscale quantum plasmonic integrated circuits.

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