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Related papers: Mn and Fe Impurities in MgB_{2}

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A theory of magnetic impurities in a 2D electron gas quantized by a strong magnetic field is formulated in terms of Friedel-Anderson theory of resonance impurity scattering. It is shown that this scattering results in an appearance of bound…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 P. Dahan , V. Fleurov , K. Kikoin , I. D. Vagner

The effects of nonmagnetic impurities on the Q=(pi,pi) spin-fluctuation spectral weight Im chi(Q,omega) are studied within the framework of the two-dimensional Hubbard model using the random phase approximation. In the first part of the…

Strongly Correlated Electrons · Physics 2007-05-23 N. Bulut

We address the effect of MgO impurity on the superconducting properties of MgB2. The synthesis of MgB2 is very crucial because of sensitivity of Mg to oxidation which may lead to MgO as a secondary phase. Rietveld refinement was performed…

Superconductivity · Physics 2015-06-19 Dharmendra Kumar Singh , Brajesh Tiwari , Rajveer Jha , H. Kishan , V. P. S. Awana

Magnetic impurities adsorbed on graphene are coupled magnetically via the itinerant electrons. This interaction opens a gap in the band structure of graphene. The result strongly depends on how the magnetic impurities are distributed. While…

Strongly Correlated Electrons · Physics 2010-10-05 Maria Daghofer , Nan Zheng , Adriana Moreo

The nature of low-impurity ferromagnetism remains a challenging problem in the solid-state community. Despite initial experiments dating back to the mid-20th century, a comprehensive theoretical explanation and reliable ab initio…

A microscopic model of indirect exchange interaction between transition metal impurities in dilute magnetic semiconductors (DMS) is proposed. The hybridization of the impurity d-electrons with the heavy hole band states is largely…

Strongly Correlated Electrons · Physics 2009-11-10 P. M. Krstajic , F. M. Peeters , V. A. Ivanov , V. Fleurov , K. Kikoin

A report of progress in spintronics-related works involving group III nitrides is given emphasizing contradictory opinions concerning basics characteristics of these materials. The actual position of magnetic impurities in the GaN lattice…

Materials Science · Physics 2015-06-24 Tomasz Dietl

Nonmagnetic Zn impurities are known to strongly suppress superconductivity. We review their effects on the spin excitation spectrum in $\rm YBa_2Cu_3O_{7}$, as investigated by inelastic neutron scattering measurements.

Superconductivity · Physics 2007-05-23 Y. Sidis , P. Bourges , B. Keimer , L. P. Regnault , J. Bossy , A. Ivanov , B. Hennion , P. Gautier-Picard , G. Collin

We study the entanglement of magnetic impurities in an environment of electrons through successive scattering while an external magnetic field is applied. We show that the dynamics of the problem can be approximately described by a reduced…

Strongly Correlated Electrons · Physics 2014-12-10 Alexandros Metavitsiadis , Raoul Dillenschneider , Sebastian Eggert

We investigate Mn substitution at the Fe site in PrFe1-xMnxAsO0.7F0.3 (0 to 0.1) using structural, Raman, density functional theory (DFT), transport, and magnetic measurements. X-ray diffraction and Raman analyses confirm preferential Mn…

We study spectra for a 2D electron in the lowest Landau level with randomly distributed, repulsively correlated electric impurities. The lowest energy band reflects an effective magnetic field downshifted by an integer multiple of the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Alfred Scharff Goldhaber , M. L. Horner

We present a theoretical study using density functional calculations of the structural, electronic and magnetic properties of 3d transition metal, noble metal and Zn atoms interacting with carbon monovacancies in graphene. We pay special…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Elton J. G. Santos , Andres Ayuela , Daniel Sanchez-Portal

I calculated the effect of magnetic impurities on the normal and superconductive properties of a multiband s-wave superconductor by direct solution of the two-band Eliashberg equations. In this way I determined the critical temperature, the…

Superconductivity · Physics 2007-05-23 G. A. Ummarino

The magnetization behaviors of GdMn2Ge2 and TbMn2Ge2 in the bulk and in the fine particles obtained by high-energy ball-milling are compared. Pronounced modificayions in the spontaneous, remnent and high-field magnetization in the fine…

Strongly Correlated Electrons · Physics 2015-05-18 K. Mukherjee , Kartik K Iyer , E. V. Sampathkumaran

A large number of experimental facts and theoretical arguments favor a two-gap model for superconductivity in MgB$_{2}$. However, this model predicts strong suppression of the critical temperature by interband impurity scattering and,…

We consider a magnetic impurity in a spin liquid state of a magnetic system which is close to the quantum phase transition to the magnetically ordered state. There is similarity between this problem and the Kondo problem. We derive the…

Strongly Correlated Electrons · Physics 2009-10-31 O. P. Sushkov

The pointlike impurity scattering is studied for a superconductor with different pairing symmetries based on a minimal two band model proposed by S. Raghu $et$ $al.$ [Phys. Rev. B {\bf 77}, R220503 (2008)], and the self-consistent…

Superconductivity · Physics 2009-11-10 Tao Zhou , Xiang Hu , Jian-Xin Zhu , C. S. Ting

We calculate the upper critical field, Hc2(T), due to the orbital pair breaking in disordered superconductors without inversion symmetry. Differences from the usual centrosymmetric case are highlighted. The linearized gap equations in…

Superconductivity · Physics 2009-11-13 K. V. Samokhin

The effect of nonmagnetic impurities and the effective masses on the spin-dependent transport in a ferromagnet-normal metal-ferromagnet junction is investigated on the basis of a two-band model. Our results show that impurities and the…

Strongly Correlated Electrons · Physics 2009-11-07 Zhen-Gang Zhu , Gang Su , Biao Jin , Qing-Rong Zheng

We investigate how magnetic impurities may affect a system exhibiting charge-density wave (CDW) in its ground state. We consider a disordered Hubbard-Holstein model with a homogeneous electron-phonon interaction, but with a (randomly…

Strongly Correlated Electrons · Physics 2024-04-09 Sebastião dos Anjos Sousa-Júnior , Raimundo R. dos Santos , Natanael C. Costa