Nonlocal correlation represents the key feature of quantum mechanics, which is exploited as a resource in quantum information processing. However, the loophole issues hamper the practical ...applications. We report the first demonstration of steering nonlocality with detection loophole closed at telecommunication wavelengths. In this endeavour, we design and fabricate a low-loss silicon chip for efficient entanglement generation, and further apply the direct modulation technique to its optical pump to eliminate phase-encoding loss at the steering side. The newly proposed phase-encoding measurement setting adapts to an ultra-fast modulation rate (GHz). Consequently, we build a fiber-optic setup that can overcome the detection efficiency that is required by quantum steering with multiple measurement settings. Our setup provides an immediate platform for exploring applications based on steering nonlocality, especially for quantum communication.
Vapor-phase esterification of cellulose was achieved by exposing filter paper and tunicate cellulose film to mixed vapor of trifluoroacetic anhydride (TFAA) and acetic acid (AcOH) or TFAA and acetic ...anhydride (Ac2O) at room temperature. Both treatments gave high hydrophobicity to the specimens. The hydrophobicity of TFAA/AcOH-treated sample was resistant to water immersion, but that of TFAA/Ac2O-treated sample was lost due to hydrolysis. In spite of high hydrophobicity, the bulk degree of substitution for acetyl groups was as low as 0.07, indicating localization of acetyl groups on the fibril surfaces. Detection of ester groups by X-Ray photoelectron spectroscopy corroborated this feature. Infrared spectroscopy of tunicate cellulose revealed that the esterification occurred preferentially to the weakly hydrogen-bonded hydroxyl groups. This vapor-phase process is potentially useful in modifying cellulosic materials without immersing in solvents or liquid reagents.
We derive the theoretical limit of single-photon purity of heralded single-photon sources, and accordingly demonstrate a bright, gigahertz-pulsed heralded source with the purity saturating the limit. ...Based on spontaneous four-wave mixing in a silicon spiral waveguide, this on-chip source is measured to have a coincidence rate exceeding 1.5 MHz at a coincidence to accidental (CAR) ratio of 16.77. The single-photon purity, quantified by the auto-correlation function \(g^{(2)}_h(0)\), reaches the theoretical limit with the lowest value of \(0.00094 \pm 0.00002\) obtained at a coincidence rate of 0.8 kHz. We attribute our results to effective spectral filtering as well as the coherent pump condition helped by optical injection locking.
Quantum entanglement has become an essential resource in quantum information processing. Existing works employ entangled quantum states to perform various tasks, while little attention is paid to the ...control of the resource. In this work, we propose a simple protocol to upgrade an entanglement source with access control through phase randomization at the optical pump. The enhanced source can effectively control all users in utilizing the entanglement resource to implement quantum cryptography. In addition, we show this control can act as a practical countermeasure against memory attack on device-independent quantum key distribution at a negligible cost. To demonstrate the feasibility of our protocol, we implement an experimental setup using just off-the-shelf components and characterize its performance accordingly.
We propose and demonstrate a simple protocol to upgrade a time-bin entanglement resource with access-control through binary phase randomization at the optical pump. The enhanced source can ...effectively control all users at a negligible cost.
A simple chemical modification route to confer high hydrophobicity to crystalline cellulose surface was demonstrated using tunicin whiskers as model material. An alkyenyl succinic anhydride (ASA) ...aqueous emulsion was mixed with cellulose suspension, freeze-dried, and heated to 105 degree C. The bulk degree of substitution (DS) was evaluated by FT-IR spectrometry, elemental analysis, and weight gain. The surface DS was quantified by X-ray photoelectron spectroscopy. The surface-acylated whiskers retained their morphological and crystalline integrity, but due to their surface acylation, they are readily dispersible in solvents of low polarity such as 1,4-dioxane. These whiskers can also be well dispersed in polystyrene to form a nanocomposite.
We designed, fabricated, and characterized a programmable qudit-based quantum processor on silicon. We implemented several quantum algorithms with qudits, showing the logarithmic speed-up, photon ...detection rate enhancement and accuracy improvement in the qudit-based quantum information processing.
We report the multi-path delayed-choice experiment on a large-scale integrated silicon photonic chip. Wave- and particle-nature in generalised form are characterised experimentally and the ...generalisation of Bohr's multi-path duality relation is demonstrated.
A Programmable Qudit-Based Quantum Processor Chi, Yulin; Huang, Jieshan; Zhang, Zhanchuan ...
2022 Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR),
2022-July-31
Conference Proceeding
Odprti dostop
We designed, fabricated, and characterized a programmable qudit-based quantum processor on silicon and several quantum algorithms were implemented using qudits which shows the logarithmic speed-up, ...counting rate acceleration and accuracy improvement of the qudit processor.
The wave-particle duality of quantum objects has been a center concept in quantum mechanics since its birth. For the two-path or two-slit experiment, the dual nature of quantum matter has been well ...studied in various systems. To rule out the interpretation of quanta knowing the measurement setting it will be confronted, Wheeler proposed the famous delayed-choice gedanken experiment 1 , which is an ideal platform to test the intrinsic characters of wave-particle duality. However, all these experiments to date have been focused on the two-path case.
