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We study a system of two Coulombically interacting electrons in an external harmonic potential in the presence of an on-centre Coulomb impurity. Detailed results for the dependencies of the reduced von Neumann entropy on the control…

Quantum Physics · Physics 2017-07-17 Przemyslaw Koscik

The effects of nonmagnetic impurity on the spin excitation spectra in a $d_{x^2-y^2}$-wave superconductor are examined, using the self-consistent $t$-matrix approximation. It is shown that the impurity self-energy acts to shift the position…

Superconductivity · Physics 2009-10-31 Jian-Xin Li , Wei-Guo Yin , Chang-De Gong

In conventional superconductors, magnetic impurities form an impurity band due to quantum interference of the impurity bound states, leading to suppression of the superconducting transition temperature. Such quantum interference effects can…

The influence of an impurity atom on the electrostatic behaviour of a Single Molecular Transistor (SMT) was investigated through Ab-initio calculations in a double-gated geometry. The charge stability diagram carries unique signature of the…

Mesoscale and Nanoscale Physics · Physics 2014-11-11 S. J. Ray

We consider an "impurity" with a spin degree of freedom coupled to a finite reservoir of non-interacting electrons, a system which may be realized by either a true impurity in a metallic nano-particle or a small quantum dot coupled to a…

Mesoscale and Nanoscale Physics · Physics 2009-08-06 R. K. Kaul , D. Ullmo , G. Zarand , S. Chandrasekharan , H. U. Baranger

A single impurity problem is investigated for multiband s-wave superconductors with different sign order parameters (+-s-wave superconductors) suggested in Fe-pnictide superconductors. Not only intraband but also interband scattering is…

Superconductivity · Physics 2009-08-10 Masashige Matsumoto , Mikito Koga , Hiroaki Kusunose

We investigate the effects of impurities and changing ring geometry on the energetics of quantum rings under different magnetic field strengths. We show that as the magnetic field and/or the electron number are/is increased, both the…

Strongly Correlated Electrons · Physics 2007-05-23 M. Aichinger , S. A. Chin , E. Krotscheck , E. Rasanen

We have recently shown that asymmetric lateral spin orbit coupling (LSOC) resulting from the lateral in-plane electric field of the confining potential of a side-gated quantum point contact (QPC) can be used to create a strongly spin-…

Mesoscale and Nanoscale Physics · Physics 2011-07-12 J. Wan , M. Cahay , P. P. Das , R. S. Newrock

We present a microscopic theory of the optical properties of self-assembled quantum dots doped with a single magnetic manganese (Mn) impurity and containing a controlled number of electrons. The single-particle electron and heavy-hole…

Mesoscale and Nanoscale Physics · Physics 2013-09-18 U. C. Mendes , M. Korkusinski , A. H. Trojnar , P. Hawrylak

We demonstrate that quantum interference of electronic waves that are scattered by multiple magnetic impurities in an s-wave superconductor gives rise to novel bound states. We predict that by varying the inter-impurity distance or the…

Strongly Correlated Electrons · Physics 2009-11-07 Dirk K. Morr , Nikolaos A. Stavropoulos

Effects of disorder on superconducting properties of noncentrosymmetric compounds are discussed. Elastic impurity scattering, even for scalar impurities, leads to a strongly anisotropic mixing of the electron states in the bands split by…

Superconductivity · Physics 2010-02-26 K. V. Samokhin

We investigate the effect of spin-orbit coupling on the behavior of magnetic impurity at the edge of a zigzag graphene ribbon by means of quantum Monte Carlo simulations. A peculiar interplay of Kane-Mele type spin-orbit and impurity-host…

Strongly Correlated Electrons · Physics 2013-08-09 F. M. Hu , T. O. Wehling , J. E. Gubernatis , Thomas Frauenheim , R. M. Nieminen

Heterostructures allow the realization of electronic states that are difficult to obtain in isolated systems. Exemplary is the case of quasi-one-dimensional heterostructures formed by a superconductor and a semiconductor with spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2018-05-02 Dong E. Liu , Enrico Rossi , Roman M. Lutchyn

The effect of impurities situated at different distances from a two-dimensional electron gas on the density of states in a strong magnetic field is analyzed. Based on the exact result of Brezin, Gross, and Itzykson, we calculate the density…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 I. S. Burmistrov , M. A. Skvortsov

We study the non-equilibrium dynamics of a spinful single-orbital quantum dot with an incorporated quantum mechanical spin-1/2 magnetic impurity. Due to the spin degeneracy, double occupancy is allowed, and Coulomb interaction together with…

Mesoscale and Nanoscale Physics · Physics 2012-07-30 Daniel Becker , Stephan Weiss , Michael Thorwart , Daniela Pfannkuche

Using one-dimensional spin-orbital model as a typical example of quantum spin systems with richer symmetries, we study the effect of an isolated impurity on its low energy dynamics in the gapless phase through bosonization and…

Strongly Correlated Electrons · Physics 2009-10-31 Yu-Wen Lee , Yu-Li Lee

The nonlinear ballistic conductance of three-dimensional quantum microconstrictions, which contain magnetic impurities, is investigated. The nonlinear part of the conductance, which is due to the interaction of electrons with magnetic…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 A. Namiranian , Yu. A. Kolesnichenko , A. N. Omelyanchouk

We investigate the effect due to background impurities embedded in the region of two-dimensional electron gases to the magnetotransport. These impurities are achieved by homogeneously incorporating Si atoms in single quantum wells of high…

Mesoscale and Nanoscale Physics · Physics 2015-11-26 E. P. Rugeramigabo , L. Bockhorn , R. J. Haug

We study the effects of external impurities on the shell structure in semiconductor quantum dots by using a fast response-function method for solving the Kohn-Sham equations. We perform statistics of the addition energies up to 20…

Strongly Correlated Electrons · Physics 2009-11-10 M. Aichinger , E. Rasanen

Interelectron interactions and correlations in quantum dots can lead to spontaneous symmetry breaking of the self-consistent mean field resulting in formation of Wigner molecules. With the use of spin-and-space unrestricted Hartree-Fock…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 Constantine Yannouleas , Uzi Landman