Magnetic impurities coupled antiferromagnetically to a one-dimensional Heisenberg model are studied by numerical diagonalization of chains of finite clusters. By calculating the binding energy and the correlation function, it is shown that a local singlet develops around each impurity. This holds true for systems with a single impurity, with two impurities, and for impurities forming a lattice....

Embedding calculations that find approximate solutions to the Schrödinger equation for large molecules and realistic solids are performed commonly in a three step procedure involving (i) construction of a model system with effective interactions approximating the low energy physics of the initial realistic system, (ii) mapping the model system onto an impurity Hamiltonian, and (iii) solving the...

Numerical simulations of the interchange plasma turbulence in presence medium-Z impurities (N2 , Ne, Ar) seeding have been performed using BOUT++. These simulation results are used to study impurity transport mechanism edge and scrape-off layer (SOL) regions. An analytical relation for ion density with vorticity, sources sinks, mass charge ratio has also derived. Simulation shows that Ar+ moves...

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We consider the problem of screening of an electrically charged impurity in a clean graphene sheet. When electron-electron interactions are neglected, the screening charge has a sign opposite to that of the impurity, and is localized near the impurity. Interactions between electrons smear out the induced charge density to give a largedistance tail that follows approximately, but not exactly, an...

We demonstrate analytically and numerically that the impurity mode plays a very important role in the kink scattering by a local inhomogeneity, and a sine-Gordon kink may be trapped by an impurity due to loss of its kinetic energy to excite the impurity mode. We develop a collective-coordinate approach to describe the kink—impurity interactions and calculate the threshold velocity ofkink captur...

The impurity transport simulation code TOTAL (TOroidal Transport Analysis Linkage) consisting of 1-D(dimensional) transport and 2or 3-D equilibrium is developed for analyzing tokamak and helical burning plasmas controlled by feedback scheme with gas puffing, pellet fueling injection and heating power modulations. In this code multi-species of impurity ions can be treated including neoclassical ...

We study a multichannel one-dimensional (1D) supersymmetric t−J model with an added magnetic impurity of arbitrary spin S. The antiferromagnetic impurity-electron interaction is chosen so as to preserve integrability, allowing for an exact diagonalization of the model by a Bethe Ansatz. The solution reveals that interactions in the bulk make the magnetic impurity drive both spin and charge fluc...

We study the localized magnetic states of an impurity in biased bilayer and trilayer graphene. It is found that the magnetic boundary for bilayer and trilayer graphene shows mixed features of Dirac and conventional fermions. For zero gate bias, as the impurity energy approaches the Dirac point, the impurity magnetization region diminishes for bilayer and trilayer graphene. When a gate bias is a...