Generating entangled states is a vital ingredient for quantum information engineering. Here, we investigate the entanglement generation between two quantum dots coupled to nanoring surface plasmons with asymmetric coupling strength g(1) and g(2). The dynamics of concurrence C is obtained by solving the corresponding master equation. High entanglement can be generated at appropriate times through the scatterings of the incident field and its scattered field. Furthermore, we find that maximum entanglement can be created when r≡g(1)/g(2) is the ratio of odd numbers. Contrary to intuition, relative high entanglement (C≃1) can remain even if the ratio r is far off the required values, which is useful in real experiments.
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http://dx.doi.org/10.1364/OL.37.001337 | DOI Listing |
Glob Epidemiol
December 2024
Cox Associates, Entanglement, University of Colorado at Denver, Denver, CO. USA.
Exposure-response associations between fine particulate matter (PM2.5) and mortality have been extensively studied but potential confounding by daily minimum and maximum temperatures in the weeks preceding death has not been carefully investigated. This paper seeks to close that gap by using lagged partial dependence plots (PDPs), sorted by importance, to quantify how mortality risk depends on lagged values of PM2.
View Article and Find Full Text PDFThe indistinguishable photon-pair sources are valuable in many quantum information applications, such as quantum microscopy, quantum synchronization, and quantum metrology. Based on cascaded sum-frequency generation (SFG) and spontaneous parametric downconversion (SPDC) processes, we propose and demonstrate a scheme for the generation of spatially separated broadband indistinguishable photon pairs in the telecom band by using only one piece of a fiber-pigtailed periodically poled lithium niobate waveguide in a modified Sagnac loop. The measured joint spectral intensity of the generated entangled photon pairs is 7.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Stanford Institute for Materials and Energy Sciences, Stanford Linear Accelerator Center (SLAC) National Accelerator Laboratory, Menlo Park, CA 94025.
Recent experiments suggest a new paradigm toward novel colossal magnetoresistance (CMR) in a family of materials EuM[Formula: see text]X[Formula: see text] (M [Formula: see text] Cd, In, Zn; X [Formula: see text] P, As), distinct from the traditional avenues involving Kondo-Ruderman-Kittel-Kasuya-Yosida crossovers, magnetic phase transitions with structural distortions, or topological phase transitions. Here, we use angle-resolved photoemission spectroscopy and density functional theory calculations to explore their origin, particularly focusing on EuCd[Formula: see text]P[Formula: see text]. While the low-energy spectral weight royally tracks that of the resistivity anomaly near the temperature with maximum magnetoresistance ([Formula: see text]) as expected from transport-spectroscopy correspondence, the spectra are completely incoherent and strongly suppressed with no hint of a Landau quasiparticle.
View Article and Find Full Text PDFSpontaneous parametric down-conversion (SPDC) plays a pivotal role in the field of quantum optics, especially in generating quantum entangled states. This study delves into utilizing the scattering tensor of nonlinear waveguide arrays to characterize the SPDC process and optimize its efficiency. By computing the pseudo-inverse of the third-order scattering tensor describing the nonlinear arrays for biphoton generation, we determine the optimal pump profile and array conditions that best approximate a desired output biphoton distribution.
View Article and Find Full Text PDFOrbital angular momentum (OAM) entangled photon pairs with narrow bandwidths play a crucial role in the interaction of light and quantum states of matter. In this article, we demonstrate an approach for generating OAM entangled photon pairs with a narrow bandwidth by using a single driving beam in a Rb atomic vapor cell. This single driving beam is able to simultaneously couple two atomic transitions and directly generate OAM entangled biphotons by leveraging the OAM conservation law through the spontaneous four-wave mixing (SFWM) process.
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