A structural study of correlated materials: incipient mott insulators and low-dimensional systesm.

Hidden Charge Orders in Low-Dimensional Mott Insulators

Applied Sciences ◽

10.3390/app9040784 ◽

2019 ◽

Vol 9 (4) ◽

pp. 784

Author(s):

Serena Fazzini ◽

Arianna Montorsi

Keyword(s):

Hubbard Model ◽

Density Wave ◽

Finite Size ◽

Charge Order ◽

Mott Insulators ◽

Coulomb Interactions ◽

Non Local ◽

Low Dimensional ◽

A Charge ◽

Insulating Phase

The opening of a charge gap driven by interaction is a fingerprint of the transition to a Mott insulating phase. In strongly correlated low-dimensional quantum systems, it can be associated to the ordering of hidden non-local operators. For Fermionic 1D models, in the presence of spin–charge separation and short-ranged interaction, a bosonization analysis proves that such operators are the parity and/or string charge operators. In fact, a finite fractional non-local parity charge order is also capable of characterizing some two-dimensional Mott insulators, in both the Fermionic and the bosonic cases. When string charge order takes place in 1D, degenerate edge modes with fractional charge appear, peculiar of a topological insulator. In this article, we review the above framework, and we test it to investigate through density-matrix-renormalization-group (DMRG) numerical analysis the robustness of both hidden orders at half-filling in the 1D Fermionic Hubbard model extended with long range density-density interaction. The preliminary results obtained at finite size including several neighbors in the case of dipolar, screened and unscreened repulsive Coulomb interactions, confirm the phase diagram of the standard extended Hubbard model. Besides the trivial Mott phase, the bond ordered and charge density wave insulating phases are also not destroyed by longer ranged interaction, and still manifest hidden non-local orders.

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Spin gap in low-dimensional Mott insulators with orbital degeneracy

Journal of Applied Physics ◽

10.1063/1.370241 ◽

1999 ◽

Vol 85 (8) ◽

pp. 5327-5329 ◽

Cited By ~ 1

Author(s):

L. Guidoni ◽

G. Santoro ◽

S. Sorella ◽

A. Parola ◽

E. Tosatti

Keyword(s):

Mott Insulators ◽

Spin Gap ◽

Orbital Degeneracy ◽

Low Dimensional

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Observation of Correlated Particle-Hole Pairs and String Order in Low-Dimensional Mott Insulators

Science ◽

10.1126/science.1209284 ◽

2011 ◽

Vol 334 (6053) ◽

pp. 200-203 ◽

Cited By ~ 198

Author(s):

M. Endres ◽

M. Cheneau ◽

T. Fukuhara ◽

C. Weitenberg ◽

P. Schauss ◽

...

Keyword(s):

Mott Insulators ◽

Low Dimensional

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An Ultra-Structural Study of Human Melanoma in Vivo and Vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091275 ◽

1976 ◽

Vol 34 ◽

pp. 258-259

Author(s):

James R. Gaylor ◽

Fredda Schafer ◽

Robert E. Nordquist

Keyword(s):

Endoplasmic Reticulum ◽

Golgi Apparatus ◽

Protein Aggregation ◽

Structural Study ◽

Human Melanoma ◽

Protein Matrix ◽

Early Form ◽

Endoplasmic Reticulum Protein ◽

Mitochondrial Origin

Several theories on the origin of the melanosome exist. These include the Golgi origin theory, in which a tyrosinase-rich protein is "packaged" by the Golgi apparatus, thus forming the early form of the melanosome. A second theory postulates a mitochondrial origin of melanosomes. Its author contends that the melanosome is a modified mitochondria which acquires melanin during its development. A third theory states that a pre-melanosome is formed in the smooth or rough endoplasmic reticulum. Protein aggregation is suggested by one author as a possible source of the melanosome. This fourth theory postulates that the melanosome originates when the protein products of several genetic loci aggregate in the cytoplasm of the melanocyte. It is this protein matrix on which the melanin is deposited. It was with these theories in mind that this project was undertaken.

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