We report the full implementation of a quantum cryptography protocol using a stream of single photon pulses generated by a stable and efficient source operating at room temperature. The single photon pulses are emitted on demand by a single nitrogen-vacancy color center in a diamond nanocrystal. The quantum bit error rate is less that 4.6% and the secure bit rate is 7700 bits/s. The overall performances of our system reaches a domain where single photons have a measurable advantage over an equivalent system based on attenuated light pulses.
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http://dx.doi.org/10.1103/PhysRevLett.89.187901 | DOI Listing |
J Neuroimaging
January 2025
Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea.
Background And Purpose: We investigated the relationship between serotonergic and dopaminergic specific binding transporter ratios (SBRs) over 4 years in Parkinson's disease (PD) patients. We assessed serotonergic innervation's potential compensatory role for dopaminergic denervation, association with PD symptoms, and involvement in the development of levodopa-induced dyskinesia (LID).
Methods: SBRs of the midbrain and striatum were evaluated from [I-123] N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane SPECT images at baseline and after 4 years.
Eur J Nucl Med Mol Imaging
January 2025
Department of Internal Medicine, Division of Cardiology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Objective: Tafamidis has shown potential in slowing disease progression in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). This study aimed to evaluate serial changes on [Tc]Tc-pyrophosphate (PYP) scintigraphy during tafamidis treatment for hereditary ATTR-CM.
Methods: We retrospectively analyzed a prospectively collected cohort of Ala97Ser (A97S) hereditary ATTR-CM patients treated with tafamidis (61 mg/day) and a control group comprising A97S hereditary ATTR-CM patients who had not received disease-modifying medications.
ACS Nano
January 2025
Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
Controlling the light emitted by individual molecules is instrumental to a number of advanced nanotechnologies ranging from super-resolution bioimaging and molecular sensing to quantum nanophotonics. Molecular emission can be tailored by modifying the local photonic environment, for example, by precisely placing a single molecule inside a plasmonic nanocavity with the help of DNA origami. Here, using this scalable approach, we show that commercial fluorophores may experience giant Purcell factors and Lamb shifts, reaching values on par with those recently reported in scanning tip experiments.
View Article and Find Full Text PDFACS Nano
January 2025
Institute of Photonics and of Nanotechnologies- National Researcher Council (IFN-CNR), LNESS Laboratory, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy.
Manipulating the optical landscape of single quantum dots (QDs) is essential to increase the emitted photon output, enhancing their performance as chemical sensors and single-photon sources. Micro-optical structures are typically used for this task, with the drawback of a large size compared to the embedded single emitters. Nanophotonic architectures hold the promise to modify dramatically the emission properties of QDs, boosting light-matter interactions at the nanoscale, in ultracompact devices.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Department of Electronics and Communication Engineering, SRM University, Guntur 522240, Andhra Pradesh, India.
We propose herein a metamaterial (MM) dual-band THz sensor for various biomedical sensing applications. An MM is a material engineered to have a particular property that is rarely observed in naturally occurring materials with an aperiodic subwavelength arrangement. MM properties across a wide range of frequencies, like high sensitivity and quality factors, remain challenging to obtain.
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