scholarly journals Quantum Entanglement of Monochromatic and Non-Monochromatic Photons on a Waveguide Beam Splitter

Entropy ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 49
Author(s):  
Dmitry Makarov ◽  
Yuliana Tsykareva
Keyword(s):  
Quantum Entanglement ◽  
Simple Form ◽  
Beam Splitter ◽  
Difficult Problem ◽  
Large Quantum

It is well known that the waveguide beam splitter can be used as a source for the quantum entanglement of photons. The analysis of such quantum entanglement is a difficult problem even for monochromatic photons, since the system under study is multiparametric. This paper will show that quantum entanglement can be represented in a simple form not only for monochromatic photons but also for non-monochromatic ones. It will be shown that quantum entanglement for non-monochromatic photons can be very different from monochromatic photons, which can be used to create large quantum entanglement.

Quantum entanglement by a beam splitter analogous to laser mode transformation by a cylindrical lens

2021 ◽  
Author(s):  
Yung-Fu Chen ◽  
M. X. Hsieh ◽  
H. T. Ke ◽  
Y. T. Yu ◽  
Hsing-Chih Liang ◽  
...  
Keyword(s):  
Quantum Entanglement ◽  
Beam Splitter ◽  
Cylindrical Lens ◽  
Laser Mode ◽  
Mode Transformation

scholarly journals Simple representation of the quantum entanglement of coupled harmonic oscillators in terms of the reflection coefficient

2021 ◽  
Vol 2086 (1) ◽  
pp. 012171
Author(s):  
Yu V Tsykareva ◽  
D N Makarov
Keyword(s):  
Reflection Coefficient ◽  
Harmonic Oscillator ◽  
Quantum Entanglement ◽  
Simple Form ◽  
Harmonic Oscillators ◽  
Quantum Metrology ◽  
Molecular Chemistry ◽  
Coupled Harmonic Oscillators ◽  
Modern Physics ◽  
Coupled Harmonic Oscillator

Abstract Quantum entanglement of coupled harmonic oscillators is frequently applied in quantum and non-linear physics, molecular chemistry and biophysics, which is why its study is of a great interest for modern physics. In this work a quantum entanglement of a coupled harmonic oscillator in a simple form was found. This simple form is presented as a single parameter – reflection coefficient R. All parameters of the studied system are included in the R coefficient. It is shown that the derivation of the expression can have applications in quantum optics, in particular in quantum metrology.

scholarly journals Quantum entanglement and statistics of photons on a beam splitter in the form of coupled waveguides

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
D. N. Makarov ◽  
E. S. Gusarevich ◽  
A. A. Goshev ◽  
K. A. Makarova ◽  
S. N. Kapustin ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Transmission Coefficient ◽  
Quantum Entanglement ◽  
Beam Splitter ◽  
Photon Statistics ◽  
Frequency Dependent ◽  
Coupled Waveguides

AbstractIt is well known that a beam splitter (BS) can be used as a source of photon quantum entanglement. This is due to the fact that the statistics of photons changes at the output ports of the BS. Usually, quantum entanglement and photon statistics take into account the constancy of the reflection coefficient R or the transmission coefficient T of the BS, where $$R + T = 1$$ R + T = 1 . It has recently been shown that if BS is used in the form of coupled waveguides, the coefficients R and T will depend on the photon frequencies. In this paper, it is shown that the quantum entanglement and statistics of photons at the output ports of a BS can change significantly if a BS is used in the form of coupled waveguides, where the coefficients R and T are frequency-dependent.

Background Fitting in the Low-Loss Region of Electron Energy Loss Spectra

1990 ◽  
Vol 48 (2) ◽  
pp. 56-57
Author(s):  
C P Scott ◽  
A J Craven ◽  
C J Gilmore ◽  
A W Bowen
Keyword(s):  
Energy Loss ◽  
Multiple Scattering ◽  
Simple Form ◽  
Single Scattering ◽  
Low Loss ◽  
Characteristic Energy ◽  
Normal Method ◽  
Fitting In ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

The normal method of background subtraction in quantitative EELS analysis involves fitting an expression of the form I=AE-r to an energy window preceding the edge of interest; E is energy loss, A and r are fitting parameters. The calculated fit is then extrapolated under the edge, allowing the required signal to be extracted. In the case where the characteristic energy loss is small (E < 100eV), the background does not approximate to this simple form. One cause of this is multiple scattering. Even if the effects of multiple scattering are removed by deconvolution, it is not clear that the background from the recovered single scattering distribution follows this simple form, and, in any case, deconvolution can introduce artefacts.The above difficulties are particularly severe in the case of Al-Li alloys, where the Li K edge at ~52eV overlaps the Al L2,3 edge at ~72eV, and sharp plasmon peaks occur at intervals of ~15eV in the low loss region. An alternative background fitting technique, based on the work of Zanchi et al, has been tested on spectra taken from pure Al films, with a view to extending the analysis to Al-Li alloys.

CO2 Activation on Heterostructures of Bi2O3-Nanocluster Modified TiO2: Promoting the Critical First Step in CO2 Conversion

2018 ◽  
Author(s):  
Michael Nolan
Keyword(s):  
Metal Oxide ◽  
Density Functional ◽  
Initial Step ◽  
Difficult Problem ◽  
Carbonate Formation ◽  
Structural Distortions ◽  
Strong Adsorption ◽  
Two Factors ◽  
Key Steps ◽  
Recent Experimental Work

The conversion of CO<sub>2</sub> to fuels is of significant importance in enabling the production of sustainable fuels, contributing to alleviating greenhouse gas emissions. While there are a number of key steps required to convert CO<sub>2</sub>, the initial step of adsorption and activation by the catalyst is critical. Well-known metal oxides such as oxidised TiO<sub>2</sub> or CeO<sub>2</sub> are unable to promote this step. In addressing this difficult problem, recent experimental work shows the potential for bismuth-containing materials to activate and convert CO<sub>2</sub>, but the origin of this activity is not yet clear. Additionally, nanostructures can show enhanced activity towards CO<sub>2</sub>. In this paper we present density functional theory (DFT) simulations of CO<sub>2</sub> activation on heterostructured materials composed of extended rutile and anatase TiO<sub>2</sub> surfaces modified with nanoclusters with Bi<sub>2</sub>O<sub>3</sub> stoichiometry. These heterostructures show low coordinated Bi sites in the nanoclusters and a valence band edge that is dominated by Bi-O states. These two factors mean that supported Bi<sub>2</sub>O<sub>3</sub> nanoclusters are able to adsorb and activate CO<sub>2</sub>. Computed adsorption energies lie in the range of -0.54 eV to -1.01 eV. In these strong adsorption modes, CO<sub>2</sub> is activated, in which the molecule bends giving O-C-O angles of 126 - 130<sup>o</sup> and elongation of C-O distances up to 1.28 Å, with no carbonate formation. The electronic properties show a strong CO<sub>2</sub>-Bi-oxygen interaction that drives the interaction of CO<sub>2</sub> to induce the structural distortions. Bi<sub>2</sub>O<sub>3</sub>-TiO<sub>2</sub> heterostructures can be reduced to form Bi<sup>2+</sup> and Ti<sup>3+</sup> species. The interaction of CO<sub>2</sub> with this electron-rich, reduced system can produce CO directly, reoxidising the heterostructure or form an activated carboxyl species (CO<sub>2</sub><sup>-</sup>) through electron transfer from the heterostructure to CO<sub>2</sub>. These results highlight that a semiconducting metal oxide modified with suitable metal oxide nanoclusters can activate CO<sub>2</sub>, thus overcoming the difficulties associated with the difficult first step in CO<sub>2</sub> conversion.

Biochemical Markers in Patients with Readmission for Congestive Heart Failure

2018 ◽  
Vol 69 (7) ◽  
pp. 1687-1691
Author(s):  
Razan Al Namat ◽  
Mihai Constantin ◽  
Ionela Larisa Miftode ◽  
Andrei Manta ◽  
Antoniu Petris ◽  
...  
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Rural Areas ◽  
Discharge Planning ◽  
Difficult Problem ◽  
Uncontrolled Hypertension ◽  
Medical Attention ◽  
Family Doctors ◽  
Increased Risk ◽  
Risk Patients

Repetitive or recurrent hospitalizations are a general major health issue in patients with chronic disease. Congestive heart failure, is associated with a high incidence and presence of early rehospitalization, but variables in order to identify patients at increased risk and also an analysis of potentially remediable factors contributing to readmission have not been previously reported and it remains still a difficult problem. We retrospectively assessed 100 patients aged between 48-85 years old, of which 75% were men, who had been hospitalized with documentation of congestive heart failure in St. Spiridon County Emergency Hospital. They were hospitalized between 2010-2017. Even if recurrent heart failure was the most common cause for readmission or rehospitalization, other cardiac disorders and noncardiac illnesses were also accounted for readmission. Predictive factors of an increased probability of readmission included prior patient�s medical heart failure history, heart failure decompensation precipitated or accelerated by an ischaemic episode, atrial fibrillation or uncontrolled hypertension. Factors contributing to preventable readmissions included noncompliance with medications or diet, inadequate discharge planning or follow-up, failure of both social support system and the seek of a promp medical attention when symptoms reappeared. We also identified an inappropriate colaboration with family doctors especially for the patients from rural areas. Patients were more likely to cite side effects of prescribed medications rather than nonadherence as a precipitating factor for readmission. Thus, we can appreciate that early rehospitalization in patients with congestive heart failure may be avoidable in up to 50% of cases. Identification of high risk patients is possible and also necessary shortly after admission in order to identify nonpharmacological interventions designed to decrease readmission frequency.

COMPLEX PROSTHETIC REHABILITATION OF THE PATIENT WITH MALIGNANT TUMOR OF OROPHARYNGEAL REGION DURING ANTITUMOR TREATMENT: CASE REPORT

2019 ◽  
Vol 65 (2) ◽  
pp. 287-293
Author(s):  
Yekaterina Izhnina ◽  
Yekaterina Kochurova ◽  
Natalya Lapina ◽  
Karina Seferyan
Keyword(s):  
Case Report ◽  
Malignant Tumor ◽  
Methodological Approach ◽  
Difficult Problem ◽  
Prosthetic Rehabilitation ◽  
Anatomic Structure

Treatment of patients with malignant tumor of oropharyngeal region is a difficult problem due to the last detection of diseases and complex anatomic structure, despite the emergence new and improvement methods of the treatment of cancer of oropharyngeal region. Complex rehabilitation of this patients presents great difficulties due to the disturbance of breath, swallowing, speech, and the lack of a single methodological approach to treatment. It is needs to improve the effectiveness of prosthetic care for patients with malignant tumor of oropharyngeal region.

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