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Related papers: Engineering flat electronic bands in quasiperiodic…

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We revisit the question of quantum dynamics of electrons on the off-diagonal Fibonacci tight-binding model. We find that typical dynamical quantities, such as the probability of an electron to remain in its original position as a function…

Materials Science · Physics 2011-05-18 Ron Lifshitz , Shahar Even-Dar Mandel

Motivated by the recent theoretical studies on a two-dimensional (2D) chiral Hamiltonian based on the Su-Schrieffer-Heeger chains, we experimentally and computationally demonstrate that topological flat frequency bands can occur at open…

Mesoscale and Nanoscale Physics · Physics 2020-11-25 Kai Qian , Linghua Zhu , Keun Hyuk Ahn , Camelia Prodan

We have studied theoretically the effect of a tuneable lateral confinement on two-dimensional hole systems realised in III-V semiconductor heterostructures. Based on the 4x4 Luttinger description of the valence band, we have calculated…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 U. Zuelicke

A novel approach to investigation of correlation effects in the electronic structure of magnetic crystals which takes into account a frequency dependence of the self energy (so called ``LDA++ approach'') is developed. The fluctuation…

Strongly Correlated Electrons · Physics 2009-10-31 M. I. Katsnelson , A. I. Lichtenstein

We investigate the algebraic structure of flat energy bands a partial filling of which may give rise to a fractional quantum anomalous Hall effect (or a fractional Chern insulator) and a fractional quantum spin Hall effect. Both effects…

Mesoscale and Nanoscale Physics · Physics 2012-01-19 M. O. Goerbig

We performed first-principles density functional theory (DFT) and GW calculations to investigate electronic structures of bulk and few-layer PdSe2. We obtained the quasiparticle band structure of bulk PdSe2, and the obtained energy gap…

Materials Science · Physics 2021-09-02 Han-gyu Kim , Hyoung Joon Choi

We introduce the concept of "quantum geometric nesting'' (QGN) to characterize the idealized ordering tendencies of certain flat-band systems implicit in the geometric structure of the flat-band subspace. Perfect QGN implies the existence…

Strongly Correlated Electrons · Physics 2024-11-13 Zhaoyu Han , Jonah Herzog-Arbeitman , B. Andrei Bernevig , Steven A. Kivelson

Double stranded quasiperiodic copper mean arrangement has been studied in respect of their electronic property and thermoelectric signature. The two-arm network is demonstrated by a tight binding Hamiltonian. The eigenspectrum of such…

Disordered Systems and Neural Networks · Physics 2019-01-29 Amrita Mukherjee , Atanu Nandy

Quasicrystals possess long-range order but lack the translational symmetry of crystalline solids. In solid state physics, periodicity is one of the fundamental properties that prescribes the electronic band structure in crystals. In the…

Mesoscale and Nanoscale Physics · Physics 2017-07-21 Laura C. Collins , Thomas G. Witte , Rochelle Silverman , David B. Green , Kenjiro K. Gomes

Two-dimensional van der Waals heterostructures can be engineered into artificial superlattices that host flat bands with significant Berry curvature and provide a favorable environment for the emergence of novel electron dynamics. In…

Mesoscale and Nanoscale Physics · Physics 2023-07-06 Vo Tien Phong , E. J. Mele

A Hubbard model with a single, partially flat band has ferromagnetic ground states. It is shown that local stability of ferromagnetism implies its global stability in such a model: The model has only ferromagnetic ground states if there are…

Strongly Correlated Electrons · Physics 2009-10-31 Andreas Mielke

Periodic photonic structures enable precise control over the light-matter interaction through band structure engineering. Certain lattice geometries exhibit dispersionless flat bands, characterized by vanishing group velocity and diverging…

Aperiodicity and un-conventional rotational symmetries allow quasicrystalline structures to exhibit unprecedented physical and functional properties. In magnetism, artificial ferromagnetic quasicrystals exhibited knee anomalies suggesting…

Mesoscale and Nanoscale Physics · Physics 2022-05-18 Vinayak Shantaram Bhat , Sho Watanabe , Florian Kronast , Korbinian Baumgaertl , Dirk Grundler

We demonstrate that a complete class of flat-band lattices with underlying commutative local symmetries exhibit a locally fragmented Hilbert space. The equitable partition theorem ensures distinct parities for the compact localized states…

Statistical Mechanics · Physics 2025-04-11 Eloi Nicolau , Anselmo M. Marques , Ricardo G. Dias , Verònica Ahufinger

The past few years have seen a revived interest in quantum geometrical characterizations of band structures due to the rapid development of topological insulators and semi-metals. Although the metric tensor has been connected to many…

Mesoscale and Nanoscale Physics · Physics 2023-03-07 Adrien Bouhon , Abigail Timmel , Robert-Jan Slager

Within local-spin-density functional theory, we have investigated the `dissociation' of few-electron circular vertical semiconductor double quantum ring artificial molecules at zero magnetic field as a function of inter-ring distance. In a…

Mesoscale and Nanoscale Physics · Physics 2016-08-16 Francesc Malet , Manuel Barranco , Enrico Lipparini , Ricardo Mayol Martí Pi , Juan Ignacio Climente , Josep Planelles

We propose a tunable optical setup to engineer topologically nontrivial flat bands in twisted bilayer graphene under circularly polarized light. Using both analytical and numerical calculations, we demonstrate that nearly flat bands can be…

Strongly Correlated Electrons · Physics 2020-12-18 Yantao Li , H. A. Fertig , Babak Seradjeh

A model for quantum dots is proposed, in which the motion of a few electrons in a three-dimensional harmonic oscillator potential under the influence of a homogeneous magnetic field of arbitrary direction is studied. The spectrum and the…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 W. D. Heiss , R. G. Nazmitdinov

WTe$_2$ stands out as a semimetal presenting Fermi level quantum oscillations in most measured quantities under magnetic fields. However, the electronic band structure above and below the Fermi level has not been explored completely. Here…

We study the effect of quasiperiodic perturbations on one-dimensional all-bands-flat lattice models. Such networks can be diagonalized by a finite sequence of local unitary transformations parameterized by angles $\theta_i$. Without loss of…

Disordered Systems and Neural Networks · Physics 2023-04-13 Sanghoon Lee , Alexei Andreanov , Sergej Flach