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Related papers: Exciton Hierarchies in Gapped Carbon Nanotubes

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We formulate and study the effective low-energy quantum theory of interacting long-wavelength acoustic phonons in carbon nanotubes within the framework of continuum elasticity theory. A general and analytical derivation of all three- and…

Mesoscale and Nanoscale Physics · Physics 2009-05-14 A. De Martino , R. Egger , A. O. Gogolin

The electronic spectrum of metallic finite-size single-wall carbon nanotubes at low energies is derived. It is based on a tight-binding description for the interacting p_{z} electrons. Not only the forward scattering parts of the Coulomb…

Mesoscale and Nanoscale Physics · Physics 2008-07-31 Leonhard Mayrhofer , Milena Grifoni

The interaction potential of a two-dimensional system of excitons with spatially separated electron-hole layers is considered in the strong magnetic field limit. The excitons are assumed to have free dynamics in the $x$-$y$ plane, while…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 M. A. Olivares-Robles , S. E. Ulloa

The optical spectra of CdSe nanocrystals up to 55 A in diameter are analyzed in a wide range of energies from the fine structure of the low-energy excitations to the so-called high-energy transitions. We apply a symmetry-based method in two…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 J. Perez-Conde , A. K. Bhattacharjee

The electronic structure of finite-length armchair carbon nanotubes has been studied using several ab-initio and semi-empirical quantum computational techniques. The additional confinement of the electrons along the tube axis leads to the…

Materials Science · Physics 2007-05-23 Alain Rochefort , Dennis R. Salahub , Phaedon Avouris

We report that dark excitons can have a large contribution to the emission intensity in carbon nanotubes due to an efficient exciton conversion from a dark state to a bright state. Time-resolved photoluminescence measurements are used to…

Mesoscale and Nanoscale Physics · Physics 2019-12-11 A. Ishii , H. Machiya , Y. K. Kato

We present self-consistent calculations of electron transport in graphene nanoconstrictions within the Hartree approximation. We consider suspended armchair ribbons with V-shaped constrictions having perfect armchair or zigzag edges as well…

Mesoscale and Nanoscale Physics · Physics 2012-06-20 S. Ihnatsenka , G. Kirczenow

Various properties of interlayer excitons in double-layer transition metal dichalcogenides quantum dots are analyzed using a low-energy effective Hamiltonian with Coulomb interaction. We solve the single-particle Hamiltonian with and…

Mesoscale and Nanoscale Physics · Physics 2024-08-15 Xiang Liu , Zheng Tao , Wenchen Luo , Tapash Chakraborty

We report a femtosecond mid-infrared study of the broadband low-energy response of individually separated (6,5) and (7,5) single-walled carbon nanotubes. Strong photoinduced absorption is observed around 200 meV, whose transition energy,…

Mesoscale and Nanoscale Physics · Physics 2010-07-16 Jigang Wang , Matt W. Graham , Yingzhong Ma , Graham R. Fleming , Robert A. Kaindl

We investigate competing insulating phases in nearly metallic zigzag carbon nanotubes, under conditions where an applied magnetic flux approximately closes the single particle gap in one valley. Recent experiments have shown that an energy…

Mesoscale and Nanoscale Physics · Physics 2023-01-04 Assaf Voliovich , Mark S. Rudner , Yuval Oreg , Erez Berg

We derive an effective low-energy theory for metallic (armchair and non-armchair) single-wall nanotubes in the presence of an electric field perpendicular to the nanotube axis, and in the presence of magnetic fields, taking into account…

Mesoscale and Nanoscale Physics · Physics 2011-11-15 Jelena Klinovaja , Manuel J. Schmidt , Bernd Braunecker , Daniel Loss

We use atomistic tight-binding theory with a configuration interaction description of Coulomb and exchange effects to describe excitons in symmetric quantum dots in a vertical electric field. We show that field-induced manipulation of…

Mesoscale and Nanoscale Physics · Physics 2012-12-20 Garnett W. Bryant , Natalia Malkova , James Sims

The importance of finite-size effects for the electronic structure of long zigzag and armchair carbon nanotubes is studied. We analyze the electronic structure of capped (6,6), (8,0), and (9,0) single walled carbon nanotubes as a function…

Chemical Physics · Physics 2007-05-23 Oded Hod , Juan E. Peralta , Gustavo E. Scuseria

We consider dressing of excitonic properties by strongly correlated electrons in gate controlled twisted homo-bilayer heterostructures. The combined effect of the moir\'e potential and the Coulomb interaction supports the formation of…

Strongly Correlated Electrons · Physics 2022-12-16 Giacomo Mazza , Adriano Amaricci

Exciton-polaritons are mutually interacting quantum hybridizations of confined photons and electronic excitations. Here we demonstrate a system of optically guided, electrically polarized exciton-polaritons ('dipolaritons') that displays up…

Mesoscale and Nanoscale Physics · Physics 2018-04-18 Itamar Rosenberg , Dror Liran , Yotam Mazuz-Harpaz , Kenneth West , Loren Pfeiffer , Ronen Rapaport

Excitons in the weakly interacting regime can be well-described by many-body perturbation theories such as the Bethe-Salpeter equation formalism. However, for materials such as transition metal dichalcogenides moir\'e heterostructures under…

Materials Science · Physics 2026-03-16 Fangzhou Zhao , Carlos Mejuto-Zaera , Angel Rubio , Vojtěch Vlček

I develop a theory of combined exciton-cyclotron resonance (ExCR) in a low-density two-dimensional electron gas in high magnetic fields. In the presence of excess electrons an incident photon creates an exciton and simultaneously excites…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 A. B. Dzyubenko

A giant built-in electric field in the growth direction makes excitons in wide GaN/(Al, Ga)N quantum wells spatially indirect even in the absence of any external bias. Significant densities of indirect excitons can accumulate in…

We consider electron states in n-p double quantum dots defined in a semiconducting carbon nanotube (CNT) by an external potential. We describe formation of extended single-electron orbitals originating from the conduction and valence bands…

Mesoscale and Nanoscale Physics · Physics 2015-03-06 E. N. Osika , B. Szafran

The optical orientation and alignment of excitons in semiconductor indirect gap quantum dots have been studied theoretically. A special regime is analyzed in which the energy of the hyperfine interaction of an electron with lattice nuclei…

Mesoscale and Nanoscale Physics · Physics 2024-05-27 D. S. Smirnov , E. L. Ivchenko
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