Modeling electron-electron interactions in reduced-dimensional materials: Bond-charge Coulomb repulsion and dimerization in Peierls-Hubbard models

1990 ◽  
Vol 42 (1) ◽  
pp. 475-492 ◽  
Author(s):  
D. K. Campbell ◽  
J. Tinka Gammel ◽  
E. Y. Loh
Keyword(s):  
Coulomb Repulsion ◽  
Hubbard Models ◽  
Bond Charge ◽  
Electron Interactions

Bond-charge coulomb repulsion in peierls-hubbard models

1988 ◽  
Vol 38 (16) ◽  
pp. 12043-12046 ◽  
Author(s):  
D. K. Campbell ◽  
J. Tinka Gammel ◽  
E. Y. Loh
Keyword(s):  
Coulomb Repulsion ◽  
Hubbard Models ◽  
Bond Charge

scholarly journals Ferromagnetism in multiband Hubbard models: From weak to strong Coulomb repulsion

1996 ◽  
Vol 54 (6) ◽  
pp. 4056-4067 ◽  
Author(s):  
Karlo Penc ◽  
Hiroyuki Shiba ◽  
Frédéric Mila ◽  
Takuya Tsukagoshi
Keyword(s):  
Coulomb Repulsion ◽  
Hubbard Models ◽  
Strong Coulomb

scholarly journals Superlight pairs in face-centred-cubic extended Hubbard models with strong Coulomb repulsion

2022 ◽  
Author(s):  
Ganiyu Debo Adebanjo ◽  
Pavel Kornilovitch ◽  
James Peter Hague
Keyword(s):  
Transition Temperature ◽  
Three Dimensional ◽  
Coulomb Repulsion ◽  
Hubbard Models ◽  
Cubic Lattices ◽  
Wide Range ◽  
Strong Coulomb ◽  
Energy Ratios ◽  
High Transition ◽  
Fcc Structure

Abstract The majority of fulleride superconductors with unusually high transition-temperature to kinetic-energy ratios have a face-centred-cubic (FCC) structure. We demonstrate that, within extended Hubbard models with strong Coulomb repulsion, paired fermions in FCC lattices have qualitatively different properties than pairs in other three-dimensional cubic lattices. Our results show that strongly bound, light, and small pairs can be generated in FCC lattices across a wide range of the parameter space. We estimate that such pairs can Bose condense at high temperatures even if thelattice constant is large (as in the fullerides).

scholarly journals Ferromagnetism in d-Dimensional SU(n) Hubbard Models with Nearly Flat Bands

2021 ◽  
Vol 182 (1) ◽  
Author(s):  
Kensuke Tamura ◽  
Hosho Katsura
Keyword(s):  
Single Particle ◽  
Ground States ◽  
Coulomb Repulsion ◽  
Particle Spectrum ◽  
Finite Range ◽  
Rigorous Results ◽  
Hubbard Models ◽  
Flat Bands ◽  
Unit Cells ◽  
Number Of Particles

AbstractWe present rigorous results for the SU(n) Fermi–Hubbard models with finite-range hopping in d ($$\ge 2$$ ≥ 2 ) dimensions. The models are defined on a class of decorated lattices. We first study the models with flat bands at the bottom of the single-particle spectrum and prove that the ground states exhibit SU(n) ferromagnetism when the number of particles is equal to the number of unit cells. We then perturb the models by adding particular hopping terms and make the bottom bands dispersive. Under the same filling condition, it is proved that the ground states remain SU(n) ferromagnetic when the bottom bands are sufficiently flat and the Coulomb repulsion is sufficiently large.

Images and Applications of Ion Explosion Spike Pits

1990 ◽  
Vol 48 (1) ◽  
pp. 584-585
Author(s):  
P. Fraundorf ◽  
J. Tentschert
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Bulk Material ◽  
Coulomb Repulsion ◽  
The Body ◽  
Atomic Scale ◽  
Early Solar System ◽  
Transmission Electron ◽  
Nuclear Particle ◽  
Particle Tracks

Since the discovery of their etchability in the early 1960‘s, nuclear particle tracks in insulators have had a diverse and exciting history of application to problems ranging from the selective filtration of cancer cells from blood to the detection of 244Pu in the early solar system. Their usefulness stems from the fact that they are comprised of a very thin (e.g. 20-40Å) damage core which etches more rapidly than does the bulk material. In fact, because in many insulators tracks are subject to radiolysis damage (beam annealing) in the transmission electron microscope, the body of knowledge concerning etched tracks far outweighs that associated with latent (unetched) tracks in the transmission electron microscope.With the development of scanned probe microscopies with lateral resolutions on the near atomic scale, a closer look at the structure of unetched nuclear particle tracks, particularly at their point of interface with solid surfaces, is now warranted and we think possible. The ion explosion spike model of track formation, described loosely, suggests that a burst of ionization along the path of a charged particle in an insulator creates an electrostatically unstable array of adjacent ions which eject one another by Coulomb repulsion from substitutional into interstitial sites. Regardless of the mechanism, the ejection process which acts to displace atoms along the track core seems likely to operate at track entry and exit surfaces, with the added feature of mass loss at those surfaces as well. In other words, we predict pits whose size is comparable to the track core width.

scholarly journals Shaping quantum photonic states using free electrons

2021 ◽  
Vol 7 (11) ◽  
pp. eabe4270 ◽  
Author(s):  
A. Ben Hayun ◽  
O. Reinhardt ◽  
J. Nemirovsky ◽  
A. Karnieli ◽  
N. Rivera ◽  
...  
Keyword(s):  
Free Electron ◽  
Degrees Of Freedom ◽  
Free Electrons ◽  
Complete Control ◽  
Fock State ◽  
Judicious Choice ◽  
Electron Microscopes ◽  
Photonic States ◽  
Photonic Cavities ◽  
Electron Interactions

It is a long-standing goal to create light with unique quantum properties such as squeezing and entanglement. We propose the generation of quantum light using free-electron interactions, going beyond their already ubiquitous use in generating classical light. This concept is motivated by developments in electron microscopy, which recently demonstrated quantum free-electron interactions with light in photonic cavities. Such electron microscopes provide platforms for shaping quantum states of light through a judicious choice of the input light and electron states. Specifically, we show how electron energy combs implement photon displacement operations, creating displaced-Fock and displaced-squeezed states. We develop the theory for consecutive electron-cavity interactions with a common cavity and show how to generate any target Fock state. Looking forward, exploiting the degrees of freedom of electrons, light, and their interaction may achieve complete control over the quantum state of the generated light, leading to novel light statistics and correlations.

scholarly journals Erratum: Z2 characterization for three-dimensional multiband Hubbard models [Phys. Rev. Research 2 , 013299 (2020)]

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Bernhard Irsigler ◽  
Jun-Hui Zheng ◽  
Fabian Grusdt ◽  
Walter Hofstetter
Keyword(s):  
Three Dimensional ◽  
Hubbard Models
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