جستجوی مقالات مرتبط با کلیدواژه « در هم تنیدگی » در نشریات گروه « فیزیک »

The study of many-body quantum systems, that fail to thermalize in the presence of disorder, has recently attracted lots of interests. This is due to the appearance of the many-body localized phase and breakdown of eigenstate thermalization hypothesis in such systems which can be described by the local integrals of motion. In this paper, we consider a disordered spin chain in the many-body localized phase and try to study the dynamics of entanglement generation in this system using the local integrals of motion. To this end, we, first, solve the non-interacting system analytically to describe the mechanism of entanglement generation for different kinds of initial states, exactly. Then, we generalize this approach to the interacting system to learn the dynamics of entanglement generation. Finally, we discuss the physical meaning of different behaviors in the dynamics of entanglement generation in the presence and absence of interaction.‎

In this paper, the use of quantum technology in the radar system and the advantages of these radars as compared to classical radars have been analyzed. In the beginning, briefly, we present the basic structure of the theory of quantum electrodynamics, and then the role of photon in this theory and photon interactions is presented.  In the next step, the most general form of the quantum radar cross section equation is extracted. This equation is also studied through a particle-type approach and introduces single-particle and two-particle illumination. Further, this equation is written in terms of Fourier transforms, since this method will pave the way for analyzing the cross-section of a quantum radar for defense purposes with various geometries. Finally, an analysis of the radar cross-sectional equation for flat panel geometry will be plotted, and computer simulations are carried out using MATLAB software, and finally, by comparing charts drawn from MATLAB software for classical and quantum radars, to analyze and compare them.

In this work, we study entanglement dynamics in a two-qutrit systemunder the XX Hamiltonian, in the presence of Dzyaloshinskii-Moriya interaction and external magnetic field. Using the generalized concurrence as an entanglement measure, their entanglement dynamics are investigated by numerical computation and the appropriate graphs as a function of the parameters are depicted. The generalized concurrence measure changes for different values of interaction and non-phase coherence parameters can be investigated. It is observed that the entanglement dynamics variations range of these states is changed between maximum entanglement or no entanglement in qutrit systems, depending on the choice of the parameters involved.

In this paper، we have investigated the spin-dependent transport properties and electron entanglement in a mesoscopic system، which consists of two semi-infinite leads (as source and drain) separated by a typical quantum wire with a given potential. The properties studied include current-voltage characteristic، electrical conductivity، Fano factor and shot noise، and concurrence. The calculations are based on the transfer matrix method within the effective mass approximation. Using the Landauer formalism and transmission coefficient، the dependence of the considered quantities on type of potential well، length and width of potential well، energy of transmitted electron، temperature and the voltage have been theoretically studied. Also، the effect of the above-mentioned factors has been investigated in the nanostructure. The application of the present results may be useful in designing spintronice devices.