English
Related papers

Related papers: Electronic States in Two-Dimensional Triangular Co…

200 papers

Local density functional results are presented for the electron-doped metallochloronitrides A(x)ZrNCl and A(x)HfNCl, A = Li or Na, which superconduct up to 25K. The alkali non-stoichiometry is treated in a virtual crystal approximation. The…

Superconductivity · Physics 2009-10-31 R. Weht , A. Filippetti , W. E. Pickett

We propose a model intended to qualitatively capture the electron-electron interaction physics of two-dimensional electron gases formed near transition-metal oxide heterojunctions containing $t_{2g}$ electrons with a density much smaller…

Strongly Correlated Electrons · Physics 2016-01-27 John R. Tolsma , Alessandro Principi , Reza Asgari , Marco Polini , Allan H. MacDonald

We consider a system of two-dimensional electrons strongly localized by disorder. Interactions create a gap in the average tunneling density of states $\nu(E)$ at energies, E, close to the Fermi level. We derive a system of self-consistent…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Ya. M. Blanter , M. E. Raikh

We analyze the normal electronic states of Na$_{0.35}$CoO$_2$ based on the multi-orbital Hubbard model using the FLEX approximation. The fundamental electronic property of this system is drastically changed by the presence or absence of the…

Strongly Correlated Electrons · Physics 2009-11-11 Keiji Yada , Hiroshi Kontani

Secondary batteries are important energy storage devices for a mobile equipment, an electric car, and a large-scale energy storage. Nevertheless, variation of the local electronic state of the battery materials in the charge (or…

Correlated states emerge in low-dimensional systems owing to enhanced Coulomb interactions. Elucidating these states requires atomic scale characterization and delicate control capabilities. In this study, spectroscopic imaging-scanning…

We suggest that Cobalt-Oxychalcogenide layers constructed by vertex sharing CoA$_2$O$_2$ (A=S,Se,Te) tetrahedra, such as BaCoAO, are strongly correlated multi-orbital electron systems that can provide important clues on the cause of…

Strongly Correlated Electrons · Physics 2017-05-19 Congcong le , Shengshan Qin , Jiangping Hu

We report detailed Fermi surface topology and quasiparticle dynamics of the host cobaltate Na0.7CoO2. A direct mapping of the Fermi surface is carried out by angle-resolved photoemission spectroscopy (ARPES). Fermi surface at temperature…

Strongly Correlated Electrons · Physics 2009-11-11 A. P. Kuprin , D. Qian , Y. -D. Chuang , M. Foo , R. J. Cava , M. Z. Hasan

Electronic surface states in one-dimensional two-band TBA model are studied by use of the Green function method. The local density of states (LDOS) at successive atoms in a semi-infinite chain, even in the case of atoms distant from the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Jaroslaw Klos

Possible candidates for the Mg2B3Ox nanostructures observed in bulk of polycrystalline MgB2 (Ref.1) have been studied using a combination of Z-contrast imaging, electron energy loss spectroscopy (EELS) and first-principles calculations. The…

Superconductivity · Physics 2009-11-10 Juan C. Idrobo , Serdar Ogut , Taner Yildirim , Robert F. Klie , Nigel D. Browning

Using tunneling spectroscopy we have measured the spectral density of states of the mobile, two-dimensional electron system generated at the LaAlO3-SrTiO3 interface. As shown by the density of states the interface electron system differs…

We report on results of the first realistic electronic structure calculations of the Pu-based PuCoGa5 superconductor based on the dynamical mean field theory. We find that dynamical correlations due to the local Coulomb interaction between…

Strongly Correlated Electrons · Physics 2009-11-11 L. V. Pourovskii , M. I. Katsnelson , A. I. Lichtenstein

We study the ground-state entanglement properties of nanostructured Kondo systems consisting of a pair of impurity spins coupled to a background of confined electrons. The competition between the RKKY-like coupling and the Kondo effect…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Marco Nizama , Diego Frustaglia , Karen Hallberg

Colloidal cobalt-doped TiO2 (anatase) nanocrystals were synthesized and studied by electronic absorption, magnetic circular dichroism, transmission electron microscopy, magnetic susceptibility, cobalt K-shell X-ray absorption spectroscopy,…

Materials Science · Physics 2007-05-23 J. Daniel Bryan , Steve M. Heald , Scott A. Chambers , Daniel R. Gamelin

The electronic structure of the corundum-type transition-metal oxides V2O3 and Ti2O3 is studied by means of the augmented spherical wave method, based on density-functional theory and the local density approximation. Comparing the results…

Strongly Correlated Electrons · Physics 2007-05-23 V. Eyert , U. Schwingenschloegl , U. Eckern

With a treatment of the 4$f$ states of EuB$_6$ based on LDA+U method, the mixing of Eu $f$ states with B $p$ states around the X point of the Brillouin zone is shown to have unexpected consequences for the effective exchange interactions.…

Strongly Correlated Electrons · Physics 2009-11-10 J. Kunes , W. E. Pickett

At present, the most common type of cathode materials, NCA [Li_(1-x)Ni_(0.80)Co_(0.15)Al_(0.05)O_(2), x = 0 to 1], have a very high concentration of cobalt. Since cobalt is toxic and expensive, the existing design of cathode materials is…

Materials Science · Physics 2018-08-17 Kamalika Ghatak , Swastik Basu , Tridip Das , Hemant Kumar , Dibakar Datta

We have used low temperature scanning tunneling spectroscopy and atomic manipulation to study the role of surface-state electrons in the Kondo effect of an isolated cobalt atom adsorbed on Ag(111). We show that the observed Kondo signature…

Condensed Matter · Physics 2009-11-10 L. Limot , R. Berndt

Comparison is made of the electronic structure of the little-studied layered transition metal oxide LiNbO$_2$ with that of Na$_x$CoO$_2$, which has attracted tremendous interest since superconductivity was discovered in its hydrate.…

Superconductivity · Physics 2007-05-23 E. R. Ylvisaker , K. -W. Lee , W. E. Pickett

Layered cobaltates embody novel realizations of correlated quantum matter on a spin-1/2 triangular lattice. We report a high-resolution systematic photoemission study of the insulating cobaltates (Na1/2CoO2 and K1/2CoO2). Observation of…

Strongly Correlated Electrons · Physics 2009-11-11 D. Qian , L. Wray , D. Hsieh , D. Wu , L. J. Luo , N. L. Wang , A. Fedorov , R. J. Cava , L. Viciu , M. Z. Hasan