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## Influence of Landau level mixing on the properties of elementary excitations in graphene in strong magnetic field

Nanoscale Research Letters. 2012. Vol. 7. No. 134. P. 1-19.

Yurii E Lozovik, Alexey A Sokolik

Massless Dirac electrons in graphene fill Landau levels with energies scaled as square roots of their numbers. Coulomb interaction between electrons leads to mixing of different Landau levels. The relative strength of this interaction depends only on dielectric susceptibility of surrounding medium and can be large in suspended graphene. We consider influence of Landau level mixing on the properties of magnetoexcitons and magnetoplasmons—elementary electron-hole excitations in graphene in quantizing magnetic field. We show that, at small enough background dielectric screening, the mixing leads to very essential change of magnetoexciton and magnetoplasmon dispersion laws in comparison with the lowest Landau level approximation.

Alexey A. Sokolik, Yurii E. Lozovik, Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 99 No. 08-5423 P. 085423-1-085423-12

We present the theory of many-body corrections to cyclotron transition energies in graphene in strong magnetic field due to Coulomb interaction, considered in terms of the renormalized Fermi velocity. A particular emphasis is made on the recent experiments where detailed dependencies of this velocity on the Landau level filling factor for individual transitions were measured. ...

Added: March 8, 2019

A. A. Sokolik, A. D. Zabolotskiy, Yu. E. Lozovik, Physical Review B: Condensed Matter and Materials Physics 2017 Vol. 95 No. 12-5402 P. 125402-1-125402-7

In strong magnetic fields, massless electrons in graphene populate relativistic Landau levels with the square-root dependence of each level energy on its number and magnetic field. Interaction-induced deviations from this single-particle picture were observed in recent experiments on cyclotron resonance and magneto-Raman scattering. Previous attempts to calculate such deviations theoretically using the unscreened Coulomb interaction ...

Added: March 1, 2017

Andrei A. Siahlo, Andrey M. Popov, Nikolai A. Poklonski et al., Physica E: Low-Dimensional Systems and Nanostructures 2020 Vol. 115 P. 113645-1-113645-6

The scheme and operational principles of graphene-based nanoelectromechanical system (NEMS) for study of interaction between graphene and surface of a sample is proposed. In such a NEMS multilayer graphene membrane bends due to van der Waals attraction between surface of graphene membrane and surface of a sample attached to a manipulator. An analysis of the ...

Added: October 30, 2020

Irina V. Lebedeva, Andrey M. Popov, Andrey A. Knizhnik et al., Computational Materials Science 2015 Vol. 109 P. 240-247

The telescopic contact between graphene layers with a dielectric spacer is considered as a new type of graphene-based nanoelectronic devices. The tunneling current through the contacts with and without an argon spacer is calculated as a function of the overlap length, stacking of the graphene layers and voltage applied using non-equilibrium Green function formalism. A ...

Added: October 22, 2015

A. A. Melnikov, A. A. Sokolik, A. V. Frolov et al., Applied Physics Letters 2019 Vol. 114 P. 191107-1-191107-5

We have measured the ultrafast anisotropic optical response of highly doped graphene to an intense single cycle terahertz pulse. The time profile of the terahertz-induced anisotropy signal at 800 nm has minima and maxima repeating those of the pump terahertz electric field modulus. It grows with increasing carrier density and demonstrates a specific nonlinear dependence ...

Added: May 21, 2019

Б.Н. Миронов, С.А. Асеев, Sokolik A. A. et al., Журнал экспериментальной и теоретической физики 2018 Т. 154 № 3(9) С. 496-505

Исследована модификация графенового листа, полученного методом химического газофазного осаждения на медной мелкоячеистой сетке, под действием мощного фемтосекундного лазерного излучения. Установлено, что процесс длительного облучения образца в вакууме сопровождается 1) разрывом углеродных связей, о чем свидетельствует уменьшение яркости рефлексов, отвечающих дифракции электронного пучка на графене, и 2) образованием новых продуктов, о чем свидетельствуют появление новых дифракционных ...

Added: October 21, 2018

E. S. Andrianov, A. A. Zyablovsky, A. V. Dorofeenko et al., Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 98 No. 07-5411 P. 075411-1-075411-8

Plasmon spectroscopy methods are highly sensitive to the small volumes of material due to subwavelength localization of light increasing light-matter interaction. Recent research has shown a high potential of plasmon quantum generator (spaser) or amplifier (sped) for sensing in the infrared optical region. Trinitrotoluene (TNT) molecules fingerprints are considered as an example. Basing on Lindblad ...

Added: October 22, 2018

Yu.E. Lozovik, I.A. Nechepurenko, A.V. Dorofeenko, Photonics and Nanostructures - Fundamentals and Applications 2016 Vol. 21 P. 60-66

We propose an intracavity plasmon absorption spectroscopy method based on graphene active plasmonics. It is shown that the plasmonic cavity contribution to the sensitivity is proportional to the quality factor Q of the graphene plasmonic cavity and reaches two orders of magnitude. The addition of gain medium into the cavity increases the sensitivity of method. ...

Added: October 18, 2016

Alexey A. Sokolik, Andrey D. Zavolotskiy, Yurii E. Lozovik, Annals of Physics 2020 Vol. 412 P. 168001-1-168001-19

The virial and the Hellmann–Feynman theorems for massless Dirac electrons in a solid are derived and analyzed using generalized continuity equations and scaling transformations. Boundary conditions imposed on the wave function in a finite sample are shown to break the Hermiticity of the Hamiltonian resulting in additional terms in the theorems in the forms of ...

Added: October 18, 2019

Yu. E. Lozovik, A. A. Sokolik, A. D. Zabolotskiy, Physical Review B: Condensed Matter and Materials Physics 2015 Vol. 91 No. 075416 P. 1-8

Many-body effects on quantum capacitance, compressibility, renormalized Fermi velocity, kinetic and interaction energies of massless Dirac electrons in graphene, induced by the Coulomb interactions, are analyzed theoretically in the first-order, Hartree-Fock and random phase approximations. Recent experimental data on quantum capacitance and renormalized Fermi velocity are analyzed and compared with the theory. The bare Fermi ...

Added: December 24, 2014

A.I. Siahlo, A.M. Popov, N.A. Poklonski et al., Physica E: Low-Dimensional Systems and Nanostructures 2016 Vol. 84 P. 346-353

The scheme and operational principles of the nanoelectromechanical memory cell based on the bending of a multi-layer graphene membrane by the electrostatic force are proposed. An analysis of the memory cell total energy as a function of the memory cell sizes is used to determine the sizes corresponding to a bistable memory cell with the ...

Added: October 18, 2016

Vankov A., Вероника Евгеньевна Бисти, Леонид Викторович Кулик et al., Physics-Uspekhi 2015 Vol. 4 No. 58 P. 315-329

Experimental and theoretical research on neutral
excitations in a two-dimensional electron gas in a strong mag netic field is reviewed. Methods for calculating excitation en ergies in the strong-field limit for integer and noninteger filling
factors are considered. The effects of impurities and of the
nonideality of the two-dimensional system on the excitation
spectrum are examined. Experimental results that have been
obtained ...

Added: March 6, 2017

V. Kleptsyn, Schurov I., A. Okunev et al., Physical Review B: Condensed Matter and Materials Physics 2015 Vol. 92 No. 16 P. 165407

We study tunneling of charge carriers in single- and bilayer graphene. We propose an explanation for nonzero “magic angles” with 100% transmission for the case of symmetric potential barrier, as well as for their almost-survival for slightly asymmetric barrier in the bilayer graphene known previously from numerical simulations. Most importantly, we demonstrate that these magic ...

Added: October 13, 2015

A.I. Siahlo, N.A. Poklonski, A.V. Lebedev et al., PHYSICAL REVIEW MATERIALS 2018 Vol. 2 No. 03-6001 P. 1-9

Single-layer and bilayer carbon and hexagonal boron nitride nanoscrolls as well as nanoscrolls made of bilayer graphene/hexagonal boron nitride heterostructure are considered. Structures of stable states of the corresponding nanoscrolls prepared by rolling single-layer and bilayer rectangular nanoribbons are obtained based on the analytical model and numerical calculations. The lengths of nanoribbons for which stable ...

Added: October 22, 2018

Yu.E. Lozovik, Станислав Леонидович Огарков, A.A. Sokolik, Physical Review B: Condensed Matter and Materials Physics 2012 Vol. 86 No. 04-5429 P. 1-6

Condensation of pairs formed by spatially separated electrons and holes in a system of two isolated graphene layers is studied beyond the mean-field approximation. Suppression of the screening of the pairing interaction at large distances, caused by the appearance of the gap, is considered self-consistently. A mutual positive feedback between the appearance of the gap ...

Added: March 14, 2013

Burmistrov I., I.V. Gornyi, V.Yu. Kachorovskii et al., Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 97 No. 125402 P. 125402-1-125402-19

We demonstrate that a key elastic parameter of a suspended crystalline membrane—the Poisson ratio (PR) ν—is a nontrivial function of the applied stress σ and of the system size L, i.e., ν=νL(σ). We consider a generic two-dimensional membrane embedded into space of dimensionality 2+dc. (The physical situation corresponds to dc=1.) A particularly important application of our results is to freestanding graphene. We ...

Added: June 6, 2018

Lozovik Y., I.A. Nechepurenko, E.S. Andrianov et al., Physical Review B: Condensed Matter and Materials Physics 2016 Vol. 94 No. July P. 035406

The development of active and passive plasmonic devices is challenging due to the high level of dissipation in normal metals. One possible solution to this problem is using alternative materials. Graphene is a good candidate for plasmonics in the near-infrared region. In this paper, we develop a quantum theory of a graphene plasmon generator. We account for quantum correlations ...

Added: September 14, 2016

Alexey A. Sokolik, Yurii E. Lozovik, Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 100 No. 12 P. 125409-1-125409-8

Magnetoplasmons on graphene edges in quantizing magnetic fields are investigated at different Landau-level filling factors. To find the mode frequency, the optical conductivity tensor of disordered graphene in a magnetic field is calculated in the self-consistent Born approximation, and the nonlocal electromagnetic problem is solved using the Wiener-Hopf method. Magnetoplasmon dispersion relations, velocities, and attenuation ...

Added: October 18, 2019

И.А. Нечепуренко, А.В. Дорофеенко, Ю.Е. Лозовик, Журнал радиоэлектроники 2015 № 12 С. 1-17

В данной работе рассмотрен поверхностный плазмон-поляритонный лазер (спазер), который генерирует поверхностные плазмоны в графеновой чешуйке. Произведен пересмотр основных лазерных уравнений для описания спазера с учетом дисперсии материальных параметров. Выполнен последовательный вывод уравнений динамики спазера, начиная с уравнений Максвелла-Блоха. Получены уравнения динамики спазера в одномодовом приближении и скоростные уравнения. Найдены выражения для параметров уравнений через физические ...

Added: October 18, 2016

Alexey A. Sokolik, Yurii E. Lozovik, Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 97 No. 07-5416 P. 1-8

Renormalization of Landau level energies in graphene in strong magnetic field due to Coulomb interaction is studied theoretically, and calculations are compared with two experiments on carrier-density dependent scanning tunneling spectroscopy. An approximate preservation of the square-root dependence of the energies of Landau levels on their numbers and magnetic field in the presence of the ...

Added: November 28, 2017

Andrew G. Semenov, Andrei D. Zaikin, Physical Review B: Condensed Matter and Materials Physics 2013 Vol. 88 No. 5 P. 054505-1-054505-10

We investigate the effect of interacting quantum phase slips on persistent current and its fluctuations in ultrathin superconducting nanowires and nanorings pierced by the external magnetic flux. We derive the effective action for these systems and map the original problem onto an effective sine-Gordon theory on torus. We evaluate both the flux dependent persistent current ...

Added: February 9, 2015

Pelinovsky E., I. Didenkulova, A. Rybkin, Journal of Fluid Mechanics 2014 Vol. 748 P. 416-432

We present an exact analytical solution of the nonlinear shallow water theory for wave run-up in inclined channels of arbitrary cross-section, which generalizes previous studies on wave run-up for a plane beach and channels of parabolic cross-section. The solution is found using a hodograph-type transform, which extends the well-known Carrier–Greenspan transform for wave run-up on ...

Added: November 19, 2014

Окубо Ю. undefined., Journal of Physics: Conference Series 2017 Vol. 804 No. 012036 P. 1-8

We investigate the existence and the orthogonality of the generalized Jack symmetric functions which play an important role in the AGT relations. We show their orthogonality by deforming them to the generalized Macdonald symmetric functions. ...

Added: October 26, 2017

Kuntsevich A., A.V. Shupletsov, G.M. Minkov, Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 97 P. 195431-1-195431-8

The phase of quantum magneto-oscillations is often associated with the Berry phase and is widely used to
argue in favor of topological nontriviality of the system (Berry phase 2πn + π). Nevertheless, the experimentally
determined value may deviate from 2πn + π arbitrarily, therefore more care should be made analyzing the
phase of magneto-oscillations to distinguish trivial systems ...

Added: September 10, 2018