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## Entanglement of multiphoton states in polarization and quadrature variables

Laser Physics. 2019. Vol. 29. No. 12. Article 124006.

Федоров М. В.

A brief overview of entanglement characterization is given in the cases of biphoton and

multiphoton polarization states. The importance of the approach is stressed based on the

Schmidt decomposition. This method is applied to the characterization of the quadrature

entanglement in two-mode multiphoton states. The fruitfulness of this approach is illustrated

by a series of examples.

Федоров М. В., Physica Scripta 2020 Vol. 95 No. 6 Article 064001

Schmidt-decomposition formalism is proposed to be used for evaluation of the degree of
quadrature entanglement in two-mode multiphoton states. A series of examples are considered,
including analysis of the quadrature entanglement of the two-mode squeezed vacuum. Singlemode
and two-mode coherent states with stochastic phases are analyzed by the same method
though in this case features of quadrature states are ...

Added: April 6, 2021

Vintskevich S. V., Grigoriev D. A., Miklin N. I. et al., Laser Physics Letters 2020 Vol. 17 No. 3 Article 035209

Density matrices of pure multiphoton Fock polarization states and their resultant reduced density matrices of mixed states are expressed in similar ways in terms of matrices of correlators, defined as averaged products of equal numbers of creation and annihilation operators. The degree of entanglement of considered states is evaluated for various combinations of parameters of states and characters of ...

Added: April 6, 2021

Burmistrov I., Tikhonov K., Gornyi I. et al., Annals of Physics 2017 Vol. 383 P. 140-156

We study the entanglement entropy and particle number cumulants for a system of disordered noninteracting fermions in d dimensions. We show, both analytically and numerically, that for a weak disorder the entanglement entropy and the second cumulant (particle number variance) are proportional to each other with a universal coefficient. The corresponding expressions are analogous to ...

Added: June 16, 2017

Акулин В. М., Physical Review A (USA) 2015 Vol. 92 No. 4

Using geometric means, we first consider a density matrix decomposition of a multipartite quantum system of a finite dimension into two density matrices: a separable one, also known as the best separable approximation, and an essentially entangled one, which contains no product state components. We show that this convex decomposition can be achieved in practice ...

Added: November 1, 2020

Kagan M., JETP Letters 2016 Vol. 103 No. 11 P. 728-738

In this short review, we first discuss the results, which are mainly devoted to the generalizations of the famous Kohn–Luttinger mechanism of superconductivity in purely repulsive fermion systems at low electron densities. In the context of repulsive-U Hubbard model and Shubin–Vonsovsky model we consider briefly the superconducting phase diagrams and the symmetries of the order parameter ...

Added: November 18, 2016

Lozovik Y., Огарков С. Л., Sokolik A. A., Physical Review B: Condensed Matter and Materials Physics 2012 Vol. 86 No. 04-5429 P. 1-6

Condensation of pairs formed by spatially separated electrons and holes in a system of two isolated graphene layers is studied beyond the mean-field approximation. Suppression of the screening of the pairing interaction at large distances, caused by the appearance of the gap, is considered self-consistently. A mutual positive feedback between the appearance of the gap ...

Added: March 14, 2013

Nicol R., Chapman S., Vertes P. et al., Journal of Neurophysiology (США) 2012 Vol. 107 No. 5 P. 1421-1430

How do human brain networks react to dynamic changes in the sensory environment? We measured rapid changes in brain network organization in response to brief, discrete, salient auditory stimuli. We estimated network topology and distance parameters in the immediate central response period, <1 s following auditory presentation of standard tones interspersed with occasional deviant tones ...

Added: October 23, 2014

Kuzmichev S. A., Kuzmicheva T. E., Tchesnokov S. et al., Journal of Superconductivity and Novel Magnetism 2016 Vol. 29 No. 4 P. 1111-1116

We present temperature dependences of the large and the small superconducting gaps measured directly by SnS-Andreev spectroscopy in various Fe-based superconductors and MgB2. The experimental L,S(T ) are wellfitted with a two-gap model based on Moskalenko and Suhl system of equations (supplemented with a BCS integral renormalization). From the fitting procedure, we estimate the key ...

Added: March 19, 2016

Загорский Д. Л., Долуденко И., Каневский В. М. et al., Известия РАН. Серия физическая 2021 Т. 85 № 8 С. 1088-1094

FeCo and FeNi alloyed nanowires (NW) were obtained by the matrix synthesis method: the effect of the
growth voltage and the effect of using a reference electrode were studied. It is shown that the composition of
FeNi nanowires strongly depends on the growth potential (with its increase, the bcc structure is changing into
fcc), and it is also ...

Added: November 12, 2021

Maslov V., Теоретическая и математическая физика 2019 Т. 201 № 1 С. 65-83

We study the process of a nucleon separating from an atomic nucleus from the mathematical standpoint
using experimental values of the binding energy for the nucleus of the given substance. A nucleon becomes
a boson at the instant of separating from a fermionic nucleus. We study the further transformations of
boson and fermion states of separation in a ...

Added: November 1, 2019

Ружицкая Д. Д., САМОЙЛЕНКО А. А., Иванов А. Д. et al., Optoelectronics, Instrumentation and Data Processing 2017 Vol. 54 No. 1 P. 1-8

This paper presents an algorithm for processing the transmission spectra of whisperinggallery optical microcavities for use as a nanoparticle detector. The algorithm is based on the broadening of the microcavity resonance curve during precipitation of nanoparticles on the microcavity surface. Experimental results on the detection of particles are compared with Langmuir adsorption theory. The contribution ...

Added: May 25, 2018

Nagaev K., Маношин А. А., Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 102 Article 155411

We calculate the electrical and thermal conductivity of a two-dimensional electron gas with strong spin-orbit
coupling in which the scattering is dominated by electron-electron collisions. Despite the apparent absence of
Galilean invariance in the system, the two-particle scattering does not affect the electrical conductivity above
the band-crossing point where both helicity bands are filled. Below the band-crossing point ...

Added: October 14, 2021

Terekhovich V., Эпистемология и философия науки 2019 Т. 56 № 1 С. 169-184

The framework of simple opposition realism - anti-realism is not enough to analyze the views on the reality of unobservable objects of quantum theory. First, it is necessary to distinguish between realism in relation to the theory and realism in relation to the theory’s objects. Secondly, realism in relation to classical objects can be combined, ...

Added: February 12, 2020

Kolokolov I., Lebedev V., Chertkov M. et al., Journal of Lightwave Technology 2004 Vol. 22 No. 4 P. 1155-1168

This paper presents a method that allows evaluating the performance of an optical fiber system where bit errors result from a complex interplay of spontaneous noise generated in optical amplifiers and birefringent disorder of the transmission fiber. We demonstrate that in the presence of temporal fluctuations of birefringence characteristics, the bit-error rate (BER) itself is ...

Added: February 23, 2017

Morozov I., Norman G., Insepov Z. et al., Physical Review Special Topics - Accelerators and Beams 2012 Vol. 15 P. 053501

This paper describes the surface environment of the dense plasma arcs that damage rf accelerators, tokamaks, and other high gradient structures. We simulate the dense, nonideal plasma sheath near a metallic surface using molecular dynamics (MD) to evaluate sheaths in the non-Debye region for high density, low temperature plasmas. We use direct two-component MD simulations ...

Added: October 28, 2013

Kugel K., Bianconi A., Poccia N. et al., Superconductor Science and Technology 2015 Vol. 28 No. 2 P. 024005-1-024005-8

The arrested nanoscale phase separation in a two-band Hubbard model for strongly correlated charge carriers is shown to occur in a particular range in the vicinity of the topological Lifshitz transition, where the Fermi energy crosses the bottom of the narrow band and a new sheet of the Fermi surface related to the charge carriers ...

Added: March 12, 2016

Дмитриев В. В., Kutuzov M. S., Soldatov A. A. et al., JETP Letters 2019 Vol. 110 No. 11 P. 748-749

We present results of nuclear magnetic resonance (NMR) experiments in superﬂuid 3He in two samples of nematic aerogel consisting of nearly parallel mullite strands. The samples were cut from the same piece of the aerogel, but one of them was squeezed by 30% in the direction transverse to the strands. In both samples the superﬂuid ...

Added: November 21, 2019

Maslov V., Russian Journal of Mathematical Physics 2019 Vol. 26 No. 2 P. 168-173

The parameters of unstable short-living isotopes are studied from
the mathematical point of view. The values of the chemical potential
and activity parameters that determine the neutron halo arising when
the neutron separates from the nucleus of an unstable isotope are
calculated. The analogy between nuclear physics and economics is
considered from the point of view of such parameters as ...

Added: August 25, 2019

Kolokolov I., Lebedev V., Sizov G., Journal of Experimental and Theoretical Physics 2011 Vol. 140 No. 2 P. 387-400

We analyze magnetic kinematic dynamo in a conducting fluid where the stationary shear flow is accompanied by relatively weak random velocity fluctuations. The diffusionless and diffusion regimes are described. The growth rates of the magnetic field moments are related to the statistical characteristics of the flow describing divergence of the Lagrangian trajectories. The magnetic field ...

Added: February 2, 2017

Orekhov M., Russian Journal of Physical Chemistry A 2021 Vol. 95 P. 2059-2064

Molecular dynamic models are created for properties of bivalent ions in organic solvents. It is shown that molecules of the considered solvents bound to ions via oxygen atoms. A theoretical model is developed that describes the ion coordination number. The coordination number in this model is determined by the ratio between the sizes of the ...

Added: October 14, 2021

Min N., Younghun K., Scientific Reports 2018 Vol. 8 No. 1 P. 16915-1-16915-18

Sequential state discrimination is a strategy for quantum state discrimination of a sender’s quantum
states when N receivers are separately located. In this report, we propose optical designs that can
perform sequential state discrimination of two coherent states. For this purpose, we consider not
only binary phase-shifting-key (BPSK) signals but also general coherent states, with arbitrary prior
probabilities. Since ...

Added: November 16, 2020

M.: Faculty of Physics, MSU, 2017

The Low Temperature Physics Conference is an international event held every three years, under the auspices of the IUPAP through its Commission C5 on Low Temperature Physics. The aim of these conferences is to exchange information and views among the members of the international scientific community in the general field of Low Temperature Physics. It ...

Added: October 1, 2017

Katushkina O., Quemerais E., Izmodenov V. et al., JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 2017 Vol. 122 No. 11 P. 10921-10937

In this work, we present for the first time the Lyman α intensities measured by Voyager 1/UVS in 2003–2014 (at 90–130 AU from the Sun). During this period Voyager 1 measured the Lyman α emission in the outer heliosphere at an almost fixed direction close to the upwind (i.e.“ toward the interstellar flow). The data show an unexpected behavior in 2003–2009: the ...

Added: January 26, 2018

Rabinowitch A., Applied Mathematics 2010 Vol. 1 P. 1-7

Added: October 5, 2019