1,373,949 research outputs found
Investigation of the microscopic behavior of Mott insulators by means of the density functional theory and many-body methods
No full textThe objective of this work is twofold. First, we explore the performance of the density functional theory (DFT) when it is applied to solids with strong electronic correlations, such as transition metal compounds. Along this direction, particular effort is put into the refinement and development of parameterization techniques for deriving effective models on a basis of DFT calculations. Second, within the framework of the DFT, we address a number of questions related to the physics of Mott insulators, such as magnetic frustration and electron-phonon coupling (Cs2CuCl4 and Cs2CuBr4), high-temperature superconductivity (BSCCO) and doping of Mott insulators (TiOCl). In the frustrated antiferromagnets Cs2CuCl4 and Cs2CuBr4, we investigate the interplay between strong electronic correlations and magnetism on one hand and electron-lattice coupling on the other as well as the effect of this interplay on the microscopic model parameters. Another object of our investigations is the oxygen-doped cuprate superconductor BSCCO, where nano-scale electronic inhomogeneities have been observed in scanning tunneling spectroscopy experiments. By means of DFT and many-body calculations, we analyze the connection between the structural and electronic inhomogeneities and the superconducting properties of BSCCO. We use the DFT and molecular dynamic simulations to explain the microscopic origin of the persisting under doping Mott insulating state in the layered compound TiOCl
Intervista ad Andrea Zanzotto
No full textLunga intervista rilasciata da A. Zanzotto a F. Carbognin e a G. Mott nel 200
Robert A. Mott Papers
No full textRobert Mott started his public broadcasting career at Washington State University, where in 1956, he became news director of the university radio station. By 1964, he joined via nomination the television division board of directors at KWSC-TV, and in 1965, he chaired the Washington State University communications department. Mott's involvement in national organizations included serving as executive director of the National Association of Educational Broadcasting's National Education Radio Division in 1968. From there he became PBS Director of Station Relations, where he served from 1970 to 1973. In October 1975, he joined the Public Service Satellite Consortium, a nonprofit organization dedicated to the development of telecommunication technology for public service, as Director of Operations, becoming vice president in 1978. The collection contains a variety of materials relating to the Public Service Satellite Consortium and the Public Broadcasting Service
Mott insulators in disguise
No full textThe Mott transition is the phenomenon of charge localization driven solely by electron-electron interaction. The other quantum numbers carried by the electrons, i.e. the spin and, eventually, the orbital, remain instead free to delocalise through the lattice. As such, the Mott phase is characterized by a disentanglement of the charge from the other quantum numbers, making its description unaccessible to independent particle schemes, where all the electron's quantum numbers are entangled in the single particle excitation.
However, at low enough temperatures any realistic Mott insulator must get rid of the spin and, eventually, orbital entropies by some kind of ordering that occurs through a symmetry breaking mechanisms. This generically leads to a disguising of the Mott phase as a conventional band insulator, now well describable by independent particle theories.
In this Thesis we analyze the occurrence of such disguised Mott insulators in the simplest generalizations of the half-filled single-band Hubbard model: lattice models still with occupation of one electron per site, but where the electron carries an additional two valued orbital quantum number, besides the spin one. We consider two distinct mechanisms that lift the orbital degeneracy, i.e. the case of two bands equal in shape but different in bandwidth, and the case of two bands equal in bandwidth but different in shape.
The phase diagram of the former model includes a region of coexisting magnetic and orbital orders, as well as a topological Lifshitz transition from a two band metal to a single band one.
The second model with two equal bandwidth but different shape bands is designed to mimic vanadium dioxide, and thus include a coupling to antiferro-distortive lattice modes. This model accurately describes several experimental results such as the transition temperature from the monoclinic insulator to the rutile metal as well as the size and the interband character of the gap of the insulating phase. Our results underline the leading role played by the local interaction in stabilising the distorted insulator
Oral history interview with John Mott
No full textJohn Mott was born in Picher, Oklahoma, and lived there for nearly seventy years. Picher was a main hub for the lead and zinc mining industry in the United States, producing numerous mine shafts and piles of chat that years later were proven to be substantial health hazards. The contamination was so extensive that eventually the town was evacuated and shut down completely during the late 1990s and early 2000s. John Mott played a significant role in the uncovering of the contamination, as well as in the studies that contributed to the town's ultimate end
Interview with Andrew Mott
No full textThe Executive Director of the Community Learning Partnership and Senior Fellow at the Wagner School of Public Service at New York University, Andrew Mott, talked with GUNI about the implication of universities creating educational programs to prepare people for careers in community development and social change. Mott highlights the importance of innovative programmes that include a multi-disciplinary point of view, offer experiential as well as classroom learning and give priority to communities and their issues in the research system
Interview with Andrew Mott
No full textThe Executive Director of the Community Learning Partnership and Senior Fellow at the Wagner School of Public Service at New York University, Andrew Mott, talked with GUNI about the implication of universities creating educational programs to prepare people for careers in community development and social change. Mott highlights the importance of innovative programmes that include a multi-disciplinary point of view, offer experiential as well as classroom learning and give priority to communities and their issues in the research system
James Mott letter to Thomas Rotch, Mamaroneck, 24th of 8th, 1795
No full textJames Mott tells Thomas Rotch that Martha Routh, British itinerant minister visited his home. Mott asks Rotch for directions regarding the return of a carriage to the Rotch family in New Bedford. 6.6" x 7.9" (17 by 20 cm
James Mott letter to Thomas Rotch, New Rochelle, 12 mo 23d, 1808
No full textThe first section of this letter provides a home remedy for treatment of bilious fever. James Mott discusses the absence of the Rotches from important Quaker Meetings, because Charity's frail health in 1808 and 1809. The next section discusses proposed reforms to the Quaker discipline which many considered too narrowly interpreted at a time when many Quakers were abandoning their faith. James Mott, 1788-1868, a Quaker teacher and merchant was an advocate for anti-slavery and women's rights and the husband of Lucretia Mott.(1793-1880) Quaker abolitionist, reformer and proponent of women's rights. 7.7" x 9.7" (19.5 by 24.7 cm
Clarissa Mott letter to Charity Rotch, Norwalk, Connecticut, May 27
No full textClarissa Mott comments on the character of James Jackson, a vile man who has scandalized the character of Mrs. Belden and her two daughters, reporting that they were prostitutes. Jackson, addicted to profanities and gambling was on his way to Ohio after escaping the wrath of his neighbors in Connecticut. Although Mrs. Mott's husband was under no obligation to Thomas Rotch, she felt compelled to warn Charity to avoid Jackson if he arrived in the Kendal neighborhood. Mott warns that Jackson will take every opportunity to victimize women. 9" x 12.5" (20.2 by 32 cm
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