scholarly journals Localised excitation of a single photon source by a nanowaveguide

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Wei Geng ◽  
Mathieu Manceau ◽  
Nancy Rahbany ◽  
Vincent Sallet ◽  
Massimo De Vittorio ◽  
...  
Keyword(s):  
Free Space ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Single Photon Source ◽  
Semiconductor Nanowire ◽  
Space Optics ◽  
Single Photon Emitters ◽  
Optical Buses ◽  
The One ◽  
Photon Source

Abstract Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10−4 only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system.

SECURITY OF QUANTUM KEY DISTRIBUTION WITH STRONG PHASE-REFERENCE PULSE

2005 ◽  
Vol 03 (supp01) ◽  
pp. 75-86
Author(s):  
MASATO KOASHI
Keyword(s):  
Coherent State ◽  
Quantum Key Distribution ◽  
Single Photon ◽  
Key Distribution ◽  
Secret Key ◽  
Single Photon Source ◽  
Reference Pulse ◽  
High Loss ◽  
The One ◽  
Photon Source

In the BB84 protocol with a perfect single photon source, the key rate decreases linearly with the transmission η of the channel. If we simply replace this source with a weak coherent-state pulse, the key rate drops more rapidly (as O(η2)) since the presence of multiple photons favors the eavesdropper. Here we discuss the unconditional security of a quantum key distribution protocol in which bit values are encoded in the phase of a weak coherent-state pulse relative to a strong reference pulse, which is essentially the one proposed by Bennett in 1992 (the B92 scheme). We show that in the limit of high loss in the transmission channel, we can construct a secret key with a rate proportional to the transmission η of the channel.

scholarly journals A room-temperature single-photon source based on strongly interacting Rydberg atoms

Science ◽  
2018 ◽  
Vol 362 (6413) ◽  
pp. 446-449 ◽  
Author(s):  
Fabian Ripka ◽  
Harald Kübler ◽  
Robert Löw ◽  
Tilman Pfau
Keyword(s):  
Room Temperature ◽  
Rydberg Atoms ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Thermal Fluctuations ◽  
Quantum States ◽  
Destructive Interference ◽  
Single Photon Source ◽  
Many Body Systems ◽  
Photon Source

Tailored quantum states of light can be created via a transfer of collective quantum states of matter to light modes. Such collective quantum states emerge in interacting many-body systems if thermal fluctuations are overcome by sufficient interaction strengths. Therefore, ultracold temperatures or strong confinement are typically required. We show that the exaggerated interactions between Rydberg atoms allow for collective quantum states even above room temperature. The emerging Rydberg interactions lead both to suppression of multiple Rydberg state excitations and destructive interference due to polariton dephasing. We experimentally implemented a four-wave mixing scheme to demonstrate an on-demand single-photon source. The combination of glass cell technology, identical atoms, and operation around room temperature promises scalability and integrability. This approach has the potential for various applications in quantum information processing and communication.

scholarly journals Scalable integrated single-photon source

2020 ◽  
Vol 6 (50) ◽  
pp. eabc8268 ◽  
Author(s):  
Ravitej Uppu ◽  
Freja T. Pedersen ◽  
Ying Wang ◽  
Cecilie T. Olesen ◽  
Camille Papon ◽  
...  
Keyword(s):  
Quantum Information Processing ◽  
Single Photon ◽  
Long Strings ◽  
High Fidelity ◽  
Single Photons ◽  
Single Photon Source ◽  
Quantum Operations ◽  
Main Challenge ◽  
On Chip ◽  
Photon Source

Photonic qubits are key enablers for quantum information processing deployable across a distributed quantum network. An on-demand and truly scalable source of indistinguishable single photons is the essential component enabling high-fidelity photonic quantum operations. A main challenge is to overcome noise and decoherence processes to reach the steep benchmarks on generation efficiency and photon indistinguishability required for scaling up the source. We report on the realization of a deterministic single-photon source featuring near-unity indistinguishability using a quantum dot in an “on-chip” planar nanophotonic waveguide circuit. The device produces long strings of >100 single photons without any observable decrease in the mutual indistinguishability between photons. A total generation rate of 122 million photons per second is achieved, corresponding to an on-chip source efficiency of 84%. These specifications of the single-photon source are benchmarked for boson sampling and found to enable scaling into the regime of quantum advantage.

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.

On-demand single-photon source for 1.3μm telecom fiber

2005 ◽  
Vol 86 (20) ◽  
pp. 201111 ◽  
Author(s):  
M. B. Ward ◽  
O. Z. Karimov ◽  
D. C. Unitt ◽  
Z. L. Yuan ◽  
P. See ◽  
...  
Keyword(s):  
Single Photon ◽  
Single Photon Source ◽  
On Demand ◽  
Photon Source

An electrically injected quantum dot spin polarized single photon source

2010 ◽  
Vol 96 (10) ◽  
pp. 101105 ◽  
Author(s):  
Pallab Bhattacharya ◽  
Ayan Das ◽  
Debashish Basu ◽  
Wei Guo ◽  
Junseok Heo
Keyword(s):  
Quantum Dot ◽  
Single Photon ◽  
Single Photon Source ◽  
Spin Polarized ◽  
Photon Source
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