Toshiba Research Europe Limited, 208 Cambridge Science Park, Cambridge, United Kingdom.
Published: October 2008
AI Article Synopsis
Article Abstract
We investigate the evolution of quantum correlations over the lifetime of a multiphoton state. Measurements reveal time-dependent oscillations of the entanglement fidelity for photon pairs created by a single semiconductor quantum dot. The oscillations are attributed to the phase acquired in the intermediate, nondegenerate, exciton-photon state and are consistent with simulations. We conclude that emission of photon pairs by a typical quantum dot with finite polarization splitting is in fact entangled in a time-evolving state, and not classically correlated as previously regarded.
To (1) assess the accuracy of the Uscom BP+ oscillometric upper-arm professional blood pressure (BP) monitor in children and adolescents as per the AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018); (2) assess the suitability of a non-standard cuff; and (3) assess the impact of motion artefact on device accuracy and precision. Children and adolescents were recruited to fulfil the sex/cuff distribution criteria of the Universal Standard. Single arm sequential BP measurements were used, the test device measured on deflate with an altered child/adolescent algorithm, using three standard (Extra Small, Small Adult, Adult) and, as exploratory analysis, additionally in one non-standard cuff (Wide Range; WR) (arm circumferences: 12-17, 16-24, 22-32, 22-42 cm, respectively).
Localization microscopy enables imaging with resolutions that surpass the conventional optical diffraction limit. Notably, the Maximally INFormative LUminescence eXcitation (MINFLUX) method achieves super-resolution by shaping the excitation point spread function (PSF) to minimize the required photon flux for a given precision. Various beam shapes have recently been proposed to improve localization efficiency, yet their optimality remains an open question.
We present a model for the noise and inherent stochasticity of fluorescence signals in both continuous wave (CW) and time-gated (TG) conditions. When the fluorophores are subjected to an arbitrary excitation photon flux, we apply the model and compute the evolution of the probability mass function (pmf) for each quantum state comprising a fluorophore's electronic structure, and hence the dynamics of the resulting emission photon flux. Both the ensemble and stochastic models presented in this work have been verified using Monte Carlo molecular dynamic simulations that utilize the Gillespie algorithm.
Chiral objects are abundant in nature, and although the enantiomers have almost identical physical properties apart from their handedness, they can exhibit significantly different chemical properties and biological functions. This underscores the importance of sorting chiral substances. In this Letter, we demonstrate that chirality-sorting optical force pairs can be inversely generated in a tightly focused Gaussian beam by tailoring the input polarization state.
Harnessing high-dimensional entangled states of light presents a frontier for advancing quantum information technologies, from fundamental tests of quantum mechanics to enhanced computation and communication protocols. In this context, the spatial degree of freedom stands out as particularly suited for on-chip integration. But while traditional demonstrations produce and manipulate path-entangled states sequentially with discrete optical elements, continuously coupled nonlinear waveguide systems offer a promising alternative where photons can be generated and interfere along the entire propagation length, unveiling novel capabilities within a reduced footprint.
