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## Chiral tunneling through generic one-dimensional potential barriers in bilayer graphene

Physical Review B: Condensed Matter and Materials Physics. 2015. Vol. 92. No. 16. P. 165407.

V. Kleptsyn, Schurov I., A. Okunev, Zubov D., Katsnelson M. I.

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 angles are *not* protected in the case of bilayer and give an explicit example of a barrier with very small electron transmission probability for *any* angles. This means that one can lock charge carriers by a *p-n-p* (or *n-p-n*) junction *without* opening energy gap. This creates new opportunities for the construction of graphene transistors.

A. A. Melnikov, A. A. Sokolik, Frolov A. V. 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

Lozovik Y., Nechepurenko I. A., Andrianov E. S. 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

Миронов Б. Н., Асеев С. А., 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

Siahlo A. I., Popov A. M., Poklonski N. A. 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

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

Yu. E. Lozovik, A. A. Sokolik, Zabolotskiy A. D., 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

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

A. A. Sokolik, Zabolotskiy A. D., 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

Skopenkov M., Ustinov A., / Cornell University. Серия arXiv "math". 2022.

We present a new completely elementary model which describes creation, annihilation and motion of non-interacting electrons and positrons along a line. It is a modification of the model known under the names Feynman checkers, or one-dimensional quantum walk, or Ising model at imaginary temperature. The discrete model is consistent with the continuum quantum field theory, ...

Added: October 23, 2022

Siahlo A. I., Poklonski N. A., Lebedev A. V. 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, Nechepurenko I. A., Dorofeenko A. V., 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, 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

Нечепуренко И. А., Дорофеенко А. В., 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

Siahlo A., Popov A., Poklonski N. 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

Yu.E. Lozovik, Огарков С. Л., 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., Gornyi I. V., Kachorovskii V. Y. 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

Andrianov E. S., Zyablovsky A. A., Dorofeenko A. V. 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

Alexey A. Sokolik, Zavolotskiy A., 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

Кулешов В. М., Нарожный Н. Б., Федотов А. М. et al., Письма в Журнал экспериментальной и теоретической физики 2015 Т. 101 № 4 С. 282-288

Рассмотрены свойства носителей заряда в графене на подложке SiC, допированном примесью с зарядом Z. Для модифицированного на малых расстояниях кулоновского потенциала получены замкнутые аналитические уравнения, определяющие спектр носителей. Определены критические значения заряда Zcr, при которых уровень с данными квантовыми числами достигает границы валентной зоны. При Z<Zcr для низших значений орбитального момента получена зависимость положения уровня ...

Added: October 22, 2015

Kuntsevich A., Shupletsov A. V., Minkov G. M., 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

Bruning J., Grushin V. V., Dobrokhotov S. Y. et al., Теоретическая и математическая физика 2011 Т. 167 № 2 С. 171-192

We show that the Foldy-Wouthuysen transformation and its generalizations are simplified if the methods of pseudodifferential operators are used, which also allow estimating the exactness of the transition from the Dirac equation to the reduced equations for electrons and positrons. The methods and techniques used can be useful not only in studying asymptotic solutions of ...

Added: March 3, 2013

Grebenko A. K., Krasnikov D. V., Bubis A. et al., Advanced Science 2022 Vol. 9 No. 12 Article 2200217

Following the game-changing high-pressure CO (HiPco) process that
established the first facile route toward large-scale production of single-walled
carbon nanotubes, CO synthesis of cm-sized graphene crystals of ultra-high
purity grown during tens of minutes is proposed. The Boudouard reaction
serves for the first time to produce individual monolayer structures on the
surface of a metal catalyst, thereby providing a chemical ...

Added: December 11, 2022

Tarasov B., Arbuzov A., Volodin A. et al., Journal of Alloys and Compounds 2022 Vol. 896 Article 162881

The paper presents a review of the authors’ studies of advanced functional composites of graphene based materials with metals, alloys, intermetallic compounds and their hydrides, and on the creation on their basis of hydrogen-storage materials for a compact and safe hydrogen storage, electrode materials for nickel- metal hydride batteries, highly efficient catalysts for the hydrogenation ...

Added: December 28, 2021

Gayduchenko I., Xu S. G., Alymov G. et al., Nature Communications 2021 Vol. 12 No. 1 Article 543

The rectification of electromagnetic waves to direct currents is a crucial process for energy harvesting, beyond-5G wireless communications, ultra-fast science, and observational astronomy. As the radiation frequency is raised to the sub-terahertz (THz) domain, ac-to-dc conversion by conventional electronics becomes challenging and requires alternative rectification protocols. Here, we address this challenge by tunnel field-effect transistors ...

Added: September 27, 2021