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The intersection of two ferromagnetic domain walls placed on the surface of topological insulators provides a one-way beam splitter for domain-wall Dirac fermions. Based on an analytic expression for a static two-soliton magnetic texture we…

Mesoscale and Nanoscale Physics · Physics 2014-01-17 René Hammer , Walter Pötz

We calculate the dynamic polarizability under the random phase approximation for the dice lattice. This two-dimensional system gives rise to massless Dirac fermions with pseudospin-1 in the low-energy quantum excitation spectrum, providing…

Mesoscale and Nanoscale Physics · Physics 2016-05-04 John D. Malcolm , Elisabeth J. Nicol

We present a computational study of the two-phonon Raman spectra of silicene and graphene within a density-functional non-orthogonal tight-binding model. Due to the presence of linear bands close to the Fermi energy in the electronic…

Mesoscale and Nanoscale Physics · Physics 2016-04-29 Valentin N. Popov , Philippe Lambin

We investigate the resonant two-magnon Raman scattering in the two-dimensional (2D) and ladder-type Mott insulators by using a half-filled Hubbard model in the strong coupling limit. By performing numerical diagonalization calculations for…

Strongly Correlated Electrons · Physics 2009-11-07 Hiroaki Onodera , Takami Tohyama , Sadamichi Maekawa

Using an exact expression for the bi-spinor of parallel transport, we construct the Feynman propagator for Dirac fermions in the vacuum state on anti-de Sitter space-time. We compute the vacuum expectation value of the stress-energy tensor…

General Relativity and Quantum Cosmology · Physics 2015-01-05 Victor E. Ambrus , Elizabeth Winstanley

In this note, we study a melonic tensor model in $d$ dimensions based on three-index Dirac fermions with a four-fermion interaction. Summing the melonic diagrams at strong coupling allows one to define a formal large-$N$ saddle point in…

High Energy Physics - Theory · Physics 2018-04-04 Shiroman Prakash , Ritam Sinha

The great potential of Dirac electrons for plasmonics and photonics has been readily recognized after their discovery in graphene, followed by applications to smart optical devices. Dirac carriers are also found in topological insulators…

Planar topological superconductors with power-law-decaying pairing display different kinds of topological phase transitions where quasiparticles dubbed nonlocal-massive Dirac fermions emerge. These exotic particles form through long-range…

Superconductivity · Physics 2019-07-17 T. O. Puel , O. Viyuela

Three-dimensional topological insulators are characterized by insulating bulk state and metallic surface state involving Dirac fermions that behave as massless relativistic particles. These Dirac fermions are responsible for achieving a…

We present an approach for the efficient calculation of vibrational Raman intensities in periodic systems within density functional theory. The Raman intensities are computed from the second order derivative of the electronic density matrix…

Materials Science · Physics 2009-11-07 Michele Lazzeri , Francesco Mauri

We present finite-temperature, lattice Monte Carlo calculations of the particle number density, compressibility, pressure, and Tan's contact of an unpolarized system of short-range, attractively interacting spin-1/2 fermions in one spatial…

Quantum Gases · Physics 2015-03-18 M. D. Hoffman , P. D. Javernick , A. C. Loheac , W. J. Porter , E. R. Anderson , J. E. Drut

Experimentally, Raman continuum for $A_g$ and $B_g$ geometry exhibits peaks far apart from each other (about 80 to 150 $\rm cm^{-1}$) in frequency. The former is insensitive to doping over a small range where $T_c$ does not vary much…

Condensed Matter · Physics 2009-10-28 Haranath Ghosh , Manas Sardar

We show how it is possible to trap two-dimensional massless Dirac fermions in spatially inhomogeneous magnetic fields, as long as the formed magnetic quantum dot (or ring) is of a slowly decaying nature. It is found that a modulation of the…

Mesoscale and Nanoscale Physics · Physics 2016-10-11 C. A. Downing , M. E. Portnoi

Recent experiments of photon-nucleon and meson-nucleon scatterings have accumulated a lot of data for various meson production processes. One of the purposes of those experiments is to search for the missing resonances which are not…

High Energy Physics - Phenomenology · Physics 2024-12-30 Sang-Ho Kim , Yongseok Oh , Sangyeong Son , S. Sakinah , Myung-Ki Cheoun

We present a flexible and efficient ultrafast time-resolved spontaneous Raman spectroscopy setup to study collective excitation and quasi-particle dynamics in quantum matter. The setup has a broad energy tuning range extending from the…

Condensed matter systems in low dimensions exhibit emergent physics that does not exist in three dimensions. When electrons are confined to one dimension (1D), some significant electronic states appear, such as charge density wave,…

We propose a theory of two-magnon {\it resonant\/} Raman scattering from antiferromagnetic insulators, which contains information both on the magnetism and the carrier properties in the lighly doped phases. We argue that the conventional…

Condensed Matter · Physics 2009-10-22 Andrey V. Chubukov , David M. Frenkel

Tight binding electrons on a honeycomb lattice are described by an effective Dirac theory at low energies. Lowering symmetry by an alternate ionic potential ($\Delta$) generates a single-particle gap in the spectrum. We employ the dynamical…

Strongly Correlated Electrons · Physics 2012-05-30 M. Ebrahimkhas , S. A. Jafari

We report a comparative Raman spectroscopic study of the quasi-one-dimensional charge-density-wave systems \ab (A = K, Rb). The temperature and polarization dependent experiments reveal charge-coupled vibrational Raman features. The…

Strongly Correlated Electrons · Physics 2009-11-13 D. M. Sagar , D. Fausti , S. Yue , C. A. Kuntscher , S. van Smaalen , P. H. M. van Loosdrecht

We study the influence of a localized Gaussian deformation on massless Dirac fermions confined to a two-dimensional curved surface. Both in-plane and out-of-plane displacements are considered within the framework of elasticity theory. These…

Mesoscale and Nanoscale Physics · Physics 2026-02-09 Samuel B. B. Almeida , J. E. G. Silva , C. A. S. Almeida