scholarly journals Unbounded entanglement production via a dissipative impurity

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Vincenzo Alba
Keyword(s):  
Absorption Coefficient ◽  
Hydrodynamic Limit ◽  
Linear Growth ◽  
Free Fermion ◽  
Entanglement Dynamics ◽  
Logarithmic Negativity ◽  
Delta Potential

We investigate the entanglement dynamics in a free-fermion chain initially prepared in a Fermi sea and subjected to localized losses (dissipative impurity). We derive a formula describing the dynamics of the entanglement entropies in the hydrodynamic limit of long times and large intervals. The result depends only on the absorption coefficient of the effective delta potential describing the impurity in the hydrodynamic limit. Genuine dissipation-induced entanglement is certified by the linear growth of the logarithmic negativity. Finally, in the quantum Zeno regime at strong dissipation the entanglement growth is arrested (Zeno entanglement death).

scholarly journals Linear growth of marine microalgae culture

2018 ◽  
Vol 3 (1) ◽  
pp. 53-60 ◽  
Author(s):  
R. P. Trenkenshu ◽  
A. S. Lelekov ◽  
T. M. Novikova
Keyword(s):  
Absorption Coefficient ◽  
Chlorophyll A ◽  
Extinction Coefficient ◽  
Light Absorption ◽  
Linear Growth ◽  
Chlorophyll Concentration ◽  
Specific Rate ◽  
Specific Extinction Coefficient ◽  
Microalgae Culture ◽  
Light Absorption Coefficient

A new explanation for linear growth microalgae culture density is proposed. Equations describing the dependence of light absorption coefficient and the specific rate of biomass synthesis on chlorophyll concentration are obtained. The specific extinction coefficient for Tetraselmis virilis culture (0.008 m-2 · mg chlorophyll a) is calculated.

scholarly journals Evolution of entanglement wedge cross section following a global quench

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Komeil Babaei Velni ◽  
M. Reza Mohammadi Mozaffar ◽  
M.H. Vahidinia
Keyword(s):  
Cross Section ◽  
Linear Growth ◽  
Early Time ◽  
Quadratic Growth ◽  
Late Time ◽  
Zero Temperature ◽  
Information Measures ◽  
Logarithmic Negativity ◽  
Linear Behavior ◽  
Logarithmic Growth

Abstract We study the evolution of entanglement wedge cross section (EWCS) in the Vaidya geometry describing a thin shell of null matter collapsing into the AdS vacuum to form a black brane. In the holographic context, it is proposed that this quantity is dual to different information measures including entanglement of purification, reflected entropy, odd entropy and logarithmic negativity. In 2 + 1 dimensions, we present a combination of numerical and analytic results on the evolution and scaling of EWCS for strip shaped boundary subregions after a thermal quench. In the limit of large subregions, we find that the time evolution of EWCS is characterized by three different scaling regimes: an early time quadratic growth, an intermediate linear growth and a late time saturation. Further, in 3 + 1 dimensions, we examine the scaling behavior by considering thermal and electromagnetic quenches. In the case of a thermal quench, our numerical analysis supply results similar to observations made for the lower dimension. On the other hand, for electromagnetic quenches at zero temperature, an interesting feature is a departure from the linear behavior of the evolution to logarithmic growth.

scholarly journals Odd entanglement entropy and logarithmic negativity for thermofield double states

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Mostafa Ghasemi ◽  
Ali Naseh ◽  
Reza Pirmoradian
Keyword(s):  
Time Evolution ◽  
Linear Growth ◽  
Entanglement Entropy ◽  
Finite Size ◽  
Oscillatory Behavior ◽  
Finite Size Effect ◽  
Quantum Field Theories ◽  
Fixed Temperature ◽  
Logarithmic Negativity ◽  
Logarithmic Growth

Abstract We investigate the time evolution of odd entanglement entropy (OEE) and logarithmic negativity (LN) for the thermofield double (TFD) states in free scalar quantum field theories using the covariance matrix approach. To have mixed states, we choose non-complementary subsystems, either adjacent or disjoint intervals on each side of the TFD. We find that the time evolution pattern of OEE is a linear growth followed by saturation. On a circular lattice, for longer times the finite size effect demonstrates itself as oscillatory behavior. In the limit of vanishing mass, for a subsystem containing a single degree of freedom on each side of the TFD, we analytically find the effect of zero-mode on the time evolution of OEE which leads to logarithmic growth in the intermediate times. Moreover, for adjacent intervals we find that the LN is zero for times t < β/2 (half of the inverse temperature) and after that, it begins to grow linearly. For disjoint intervals at fixed temperature, the vanishing of LN is observed for times t < d/2 (half of the distance between intervals). We also find a similar delay to see linear growth of ∆S = SOEE− SEE. All these results show that the dynamics of these measures are consistent with the quasi-particle picture, of course apart from the logarithmic growth.

scholarly journals Entanglement dynamics in Rule 54: Exact results and quasiparticle picture

2021 ◽  
Vol 11 (6) ◽  
Author(s):  
Katja Klobas ◽  
Bruno Bertini
Keyword(s):  
Linear Growth ◽  
Von Neumann Entropy ◽  
Entanglement Dynamics ◽  
Von Neumann ◽  
Rényi Entropies ◽  
Quantum Quenches ◽  
Initial States ◽  
Local Observables ◽  
Quasiparticle Picture ◽  
Renyi Entropies

We study the entanglement dynamics generated by quantum quenches in the quantum cellular automaton Rule 54. We consider the evolution from a recently introduced class of solvable initial states. States in this class relax (locally) to a one-parameter family of Gibbs states and the thermalisation dynamics of local observables can be characterised exactly by means of an evolution in space. Here we show that the latter approach also gives access to the entanglement dynamics and derive exact formulas describing the asymptotic linear growth of all Rényi entropies in the thermodynamic limit and their eventual saturation for finite subsystems. While in the case of von Neumann entropy we recover exactly the predictions of the quasiparticle picture, we find no physically meaningful quasiparticle description for other Rényi entropies. Our results apply to both homogeneous and inhomogeneous quenches.

Is there a “universal” MAC equation?

1990 ◽  
Vol 48 (2) ◽  
pp. 228-229
Author(s):  
Robert E. Ogilvie
Keyword(s):  
Absorption Coefficient ◽  
Atomic Absorption ◽  
Atomic Number ◽  
X Ray ◽  
Time Period ◽  
Image Position

The search for an empirical absorption equation begins with the work of Siegbahn (1) in 1914. At that time Siegbahn showed that the value of (μ/ρ) for a given element could be expressed as a function of the wavelength (λ) of the x-ray photon by the following equationwhere C is a constant for a given material, which will have sudden jumps in value at critial absorption limits. Siegbahn found that n varied from 2.66 to 2.71 for various solids, and from 2.66 to 2.94 for various gases.Bragg and Pierce (2) , at this same time period, showed that their results on materials ranging from Al(13) to Au(79) could be represented by the followingwhere μa is the atomic absorption coefficient, Z the atomic number. Today equation (2) is known as the “Bragg-Pierce” Law. The exponent of 5/2(n) was questioned by many investigators, and that n should be closer to 3. The work of Wingardh (3) showed that the exponent of Z should be much lower, p = 2.95, however, this is much lower than that found by most investigators.

Linear growth of instabilities on a liquid metal under normal electric field

1993 ◽  
Vol 3 (8) ◽  
pp. 1201-1225 ◽  
Author(s):  
G. N�ron de Surgy ◽  
J.-P. Chabrerie ◽  
O. Denoux ◽  
J.-E. Wesfreid
Keyword(s):  
Liquid Metal ◽  
Electric Field ◽  
Linear Growth ◽  
Normal Electric Field

Linear and Nonlinear Optical Properties of Natural Dyes Freestanding Films and Application in Optical Limiting

2020 ◽  
pp. 139-143
Keyword(s):  
Absorption Coefficient ◽  
Water Solution ◽  
Optical Limiting ◽  
Refraction Index ◽  
Laser Wavelength ◽  
Solid State Laser ◽  
Natural Dyes ◽  
Linear And Nonlinear ◽  
532 Nm ◽  
Absorbance Spectra

Natural dyes were followed and prepared from a pomegranate, purple carrot, and eggplant peel. The absorbance spectra was measured in the wavelength range 300-800 nm. The linear properties measurements of the prepared natural dye freestanding films were determined include absorption coefficient (α0), extinction coefficient (κ), and linear refraction index (n). The nonlinear refractive index n2 and nonlinear absorption coefficient β2 of the natural dyes in the water solution were measured by the optical z-scan technique under a pumped solid state laser at a laser wavelength of 532 nm. The results indicated that the pomegranate dye can be promising candidates for optical limiting applications with significantly low optical limiting of 3.5 mW.

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