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The magnon exchange mechanism of ferromagnetic superconductivity (FM-superconductivity) was developed to explain in a natural way the fact that the superconductivity in $UGe_2$, $ZrZn_2$ and $URhGe$ is confined to the ferromagnetic…

Superconductivity · Physics 2009-11-07 N. Karchev

The persistent proximity of insulating and metallic phases, a puzzling characterestic of manganites, is argued to arise from the self organization of the twofold degenerate e_g orbitals of Mn into localized Jahn-Teller(JT) polaronic levels…

Strongly Correlated Electrons · Physics 2009-11-10 T. V. Ramakrishnan , H. R. Krishnamurthy , S. R. Hassan , G. V. Pai

Polarons are composite quasiparticles comprising electronic charge carriers taken together with the alterations they induce in surrounding condensed matter. Strong-coupling polarons form when electronic charge carriers become self-trapped:…

Strongly Correlated Electrons · Physics 2022-05-09 David Emin

By means of density-functional simulations for half-doped manganites, such as pseudocubic Pr0.5Ca0.5MnO3 and bilayer PrCa2Mn2O7, we discuss the occurrence of ferroelectricity and we explore its crucial relation to the crystal structure and…

Strongly Correlated Electrons · Physics 2013-10-07 Kunihiko Yamauchi , Silvia Picozzi

Electronic transport and magnetic properties of Ge1-xMnx/Ge(100) films are investigated as a function of Mn dilution. Depending on x, characteristic temperatures separate different regimes in both properties. Resistivity exhibits an…

Materials Science · Physics 2007-05-23 N. Pinto , L. Morresi , M. Ficcadenti , R. Murri , F. D'Orazio , F. Lucari , L. Boarino , G. Amato

The ultrastrong coupling of (quasi-)particles has gained considerable attention due to its application potential and richness of the underlying physics. Coupling phenomena arising due to electromagnetic interactions are well explored. In…

The nature of the polarons in the optimally doped colossal magnetoresistive (CMR) materials La0.7Ba0.3MnO3 (LBMO) and La0.7Sr0.3MnO3 (LSMO) is studied by elastic and inelastic neutron scattering. In both materials, dynamic nanoscale polaron…

Strongly Correlated Electrons · Physics 2008-12-18 Y. Chen , B. G. Ueland , J. W. Lynn , G. L. Bychkov , S. N. Barilo , Y. M. Mukovskii

We study the finite-temperature transport of electrons coupled to anharmonic local phonons. Our focus is on the high-temperature incoherent regime, where controlled calculations are possible both for weak and strong electron--phonon…

Strongly Correlated Electrons · Physics 2021-10-22 Attila Szabó , S. A. Parameswaran , Sarang Gopalakrishnan

The charge order of CE phase in half-doped manganites is studied, based on an argument that the charge-ordering is caused by the Jahn-Teller distortions of MnO6 octahedra rather than Coulomb repulsion between electrons. The uantitative…

Strongly Correlated Electrons · Physics 2007-05-23 S. Dong , S. Dai , X. Y. Yao , K. F. Wang , C. Zhu , J. -M. Liu

Polarons are among the most fundamental quasiparticles emerging in interacting many-body systems, forming already at the level of a single mobile dopant. In the context of the two-dimensional Fermi-Hubbard model, such polarons are predicted…

We argue that many properties of the half-doped manganites may be understood in terms of a new two-(eg electron)-fluid description, which is energetically favorable at intermediate Jahn-Teller (JT) coupling. This emerges from a competition…

Materials Science · Physics 2009-11-10 O. Cepas , H. R. Krishnamurthy , T. V. Ramakrishnan

It is discussed some problems of normal states of high temperature superconductors (HTS's) with d-wave pairing and next suppositions: 1) at pseudogap temperature it occurs the dimensional crossover from 3D incoherent normal state to quasi…

Superconductivity · Physics 2007-05-23 G. Sergeeva

A minimal model is proposed for the perovskite manganese oxides showing the strongly incoherent charge dynamics with a suppressed Drude weight in the ferromagnetic and metallic phase near the insulator. We investigate a generalized…

Strongly Correlated Electrons · Physics 2009-10-31 Hiroki Nakano , Yukitoshi Motome , Masatoshi Imada

We consider mechanism of exchange coupling based on interaction between electrons in nonmagnetic layer. Depending on ratio of inverse time of diffusion of electrons between ferromagnetic layers and ferromagnetic splitting of conducting…

Mesoscale and Nanoscale Physics · Physics 2009-09-29 Zyuzin A. Yu

Single crystalline (Bi,Ca)MnO3 (74< %Ca <82) were studied with neutron scattering, electron diffraction and bulk magnetic measurement. We discovered dynamic ferromagnetic spin correlations at high temperatures, which are replaced by…

Strongly Correlated Electrons · Physics 2009-10-28 Wei Bao , J. D. Axe , C. H. Chen , S-W. Cheong

We study the possibility of nanoscale phase separation in manganites in the framework of the double exchange model. The homogeneous canted state of this model is proved to be unstable toward the formation of small ferromagnetic droplets…

Strongly Correlated Electrons · Physics 2009-11-10 M. Yu. Kagan , A. V. Klaptsov , I. V. Brodsky , K. I. Kugel , A. O. Sboychakov , A. L. Rakhmanov

Aiming at understanding the origin of the electronic contribution to ferroelectric polarization in undoped manganites, we evaluate the Berry phase of orbital-polarizable Bloch electrons as an orbital ordering (OO) establishes in the…

Strongly Correlated Electrons · Physics 2011-02-25 P. Barone , K. Yamauchi , S. Picozzi

The unusual magneto-transport properties of manganites are widely believed to be caused by mixed-phase tendencies and concomitant percolative processes. However, dramatic deviations from "standard" percolation have been unveiled…

Condensed Matter · Physics 2009-11-07 J. Burgy , M. Mayr , E. Dagotto

We study intrinsic charge-carrier scattering mechanisms and determine their contribution to the transport properties of the two-dimensional ferromagnet Fe$_3$GeTe$_2$. We use state-of-the-art first-principles calculations combined with the…

The theory of Raman scattering in half-metals by optical phonons interacting with conduction electrons is developed. We evaluate the effect of electron-phonon interactions at ferromagnetic ordering in terms of the Boltzmann equation for…

Materials Science · Physics 2014-03-25 L. A. Falkovsky