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Related papers: Excitonic Effects in Two-Dimensional Massless Dira…

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We analyze the many-particle correlations that affect the optical properties of two-dimensional semiconductors. These correlations manifest themselves through the specific optical resonances such as excitons, trions, etc. Starting from the…

Mesoscale and Nanoscale Physics · Physics 2021-03-24 A. Kudlis , I. Iorsh

Two-dimensional Dirac semimetal with tilted Dirac cone has recently attracted increasing interest. Tilt of Dirac cone can be realized in a number of materials, including deformed graphene, surface state of topological crystalline insulator,…

Strongly Correlated Electrons · Physics 2018-11-21 Zhao-Kun Yang , Jing-Rong Wang , Guo-Zhu Liu

We investigate the description of excitonic effects within time-dependent density-functional theory (TDDFT). The exchange-correlation kernel f_xc introduced in TDDFT allows a clear separation of quasiparticle and excitonic effects. Using a…

Other Condensed Matter · Physics 2007-05-23 R. Stubner , I. V. Tokatly , O. Pankratov

Through resistivity measurements of an organic crystal hosting massless Dirac fermions with a charge-ordering instability, we reveal the effect of interactions among Dirac fermions on the charge transport. A low-temperature resistivity…

Strongly Correlated Electrons · Physics 2016-06-22 Dong Liu , Kyohei Ishikawa , Ryosuke Takehara , Kazuya Miyagawa , Masafumi Tamura , Kazushi Kanoda

We consider ferromagnetic instabilities of two-dimensional helical Dirac fermions hosted on the surface of three-dimensional topological insulators. We investigate ways to increase the role of interactions by means of modifying the bulk…

Strongly Correlated Electrons · Physics 2013-11-13 Matthias Sitte , Achim Rosch , Lars Fritz

The model under consideration is a two-dimensional two-component plasma, i.e., a continuous system of two species of pointlike particles of opposite charges $\pm 1$, interacting through the logarithmic Coulomb interaction. Using the exact…

Statistical Mechanics · Physics 2007-05-23 L. Šamaj , B. Jancovici

We study a two-component mixture of fermionic dipoles in two dimensions at zero temperature, interacting via a purely repulsive $1/r^3$ potential. This model can be realized with ultracold atoms or molecules, when their dipole moments are…

Searching for new states of matter and unusual quasiparticles in emerging materials and especially low-dimensional systems is one of the major trends in contemporary condensed matter physics. Dirac materials, which host quasiparticles which…

Mesoscale and Nanoscale Physics · Physics 2017-10-13 C. A. Downing , M. E. Portnoi

We show how strongly interacting two-dimensional Dirac fermions can be realized with ultracold atoms in a two-dimensional optical square lattice with an experimentally realistic, inherent gauge field, which breaks time-reversal and…

Quantum Gases · Physics 2015-05-13 Lih-King Lim , Achilleas Lazarides , Andreas Hemmerich , C. Morais Smith

We study localization properties of two-dimensional Dirac fermions subject to a power-law-correlated random vector potential describing, e.g., the effect of "ripples" in graphene. By using a variety of techniques (low-order perturbation…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 D. V. Khveshchenko

We study the dynamics of the half-filled zeroth Landau level of Dirac fermions using mirror symmetry, a supersymmetric duality between certain pairs of $2+1$-dimensional theories. We show that the half-filled zeroth Landau level of a pair…

Strongly Correlated Electrons · Physics 2015-12-09 Shamit Kachru , Michael Mulligan , Gonzalo Torroba , Huajia Wang

We report ab initio calculations of the dielectric function of six mono- and bilayer molybdenum dichalcogenides based in a Bethe Salpether equation+G$_0$W$_0$ ansatz, focussing on the excitonic transitions dominating the absorption spectrum…

Materials Science · Physics 2016-11-17 Roland Gillen , Janina Maultzsch

In the dilute limit, the properties of fermionic lattice models with short-range attractive interactions converge to those of a dilute Fermi gas in continuum space. We investigate this connection using mean-field and we show that the…

Quantum Gases · Physics 2012-01-31 A. Privitera , M. Capone

The damping rate of two-dimensional massless Dirac fermions exhibit non-Fermi liquid behavior, $\propto \epsilon^{1/2}$, due to gauge field at zero temperature and zero chemical potential. We study the fate of this behavior at finite…

Strongly Correlated Electrons · Physics 2015-11-23 Jing-Rong Wang , Guo-Zhu Liu

Based on a recent exchange--correlation kernel developed within Time--Dependent--Density--Functional Theory we derive a practical and general expression for the three--point vertex function. We show that excitonic effects in LiF strongly…

Materials Science · Physics 2007-05-23 Andrea Marini Angel Rubio

A few years ago some attention has been given to a fermionic action on the lattice, with a Wilson-like term which is chirally invariant but breaks the hypercubic space-time lattice symmetry. This action describes two Dirac fields in the…

High Energy Physics - Lattice · Physics 2009-10-22 Mario Pernici

It is argued that the specific heat of $N$ massless Dirac fermions in 2 spatial dimensions interacting with 1/r Coulomb interactions is suppressed logarithmically relative to its non-interacting counterpart. The (dimensionless) coefficient…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Oskar Vafek

We present a description of vacuum polarization in a circular Dirac quantum dot in two spatial dimensions assuming $\alpha$ - the relative strength of the Coulomb interaction small enough to render an approximation with a single electron…

Mesoscale and Nanoscale Physics · Physics 2017-12-13 V. Raca , M. V. Milovanović

The coupling between a 2D semiconductor quantum well and an optical cavity gives rise to combined light-matter excitations, the exciton-polaritons. These were usually measured when the conduction band is empty, making the single polariton…

Strongly Correlated Electrons · Physics 2017-11-01 Dimitri Pimenov , Jan von Delft , Leonid Glazman , Moshe Goldstein

We develop an approximation-free Diagrammatic Monte Carlo technique to study fermionic particles interacting with each other simultaneously through both an attractive Coulomb potential and bosonic excitations of the underlying medium.…

Strongly Correlated Electrons · Physics 2009-11-13 Evgeni Burovski , Holger Fehske , Andrei S. Mishchenko