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相关论文: Optical valleytronics in gapped graphene

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Strongly coupling materials to cavity fields can affect their electronic properties altering the phases of matter. We study the monolayer graphene whose electrons are coupled to both left and right circularly polarized photons, and…

介观与纳米尺度物理 · 物理学 2024-11-26 Ceren B. Dag , Vasil Rokaj

Twisting bilayer sheets of graphene have been proven to be an efficient way to manipulate the electronic Dirac-like properties, resulting in flat bands at magic angles. Inspired by the electronic model, we develop a continuum model for the…

We start with the silicene or germanene single-particle Hamiltonian in buckled 2D hexagonal lattices expressed in terms of Dirac matrices in the Weyl basis. The Hamiltonian of these systems comprises of the Dirac kinetic energy, a mass gap…

介观与纳米尺度物理 · 物理学 2014-05-20 Partha Goswami

An analysis of electron transport in graphene is presented in the presence of various arrangement of delta-function like magnetic barriers. The motion through one such barrier gives an unusual non specular refraction leading to asymmetric…

介观与纳米尺度物理 · 物理学 2009-07-09 Sankalpa Ghosh , Manish Sharma

The low-energy theory of the surface of the topological crystalline insulator (TCI) is characterized by four Dirac cones anisotropic into the $x$ and $y$ directions. Recent experiments have shown that the band gap can be introduced in these…

介观与纳米尺度物理 · 物理学 2014-06-03 Motohiko Ezawa

We present a description of the energy loss of a charged particle moving parallel to a graphene layer and graphene double layers. Specifically, we compare the stopping power of the plasma oscillations for these two configurations in the…

材料科学 · 物理学 2015-05-28 Godfrey Gumbs , O. Roslyak , Danhong Huang , Antonios Balassis

The success of photonic crystal fibres relies largely on the endless variety of two-dimensional photonic crystals in the cross-section. Here, we propose a topological bandgap fibre whose bandgaps along in-plane directions are opened by…

光学 · 物理学 2020-12-24 Hao Lin , Ling Lu

Guiding electronic waves in a manner similar to photon transmission in optical fibers is key for developing the electron-optics toolbox. Here we outline a `weak guiding' approach, in which efficient diffraction around disorder results in…

介观与纳米尺度物理 · 物理学 2015-12-15 Kamphol Akkaravarawong , Oles Shtanko , Leonid Levitov

We have performed low temperature scanning tunneling spectroscopy measurements on exfoliated bilayer graphene on SiO2. By varying the back gate voltage we observed a linear shift of the Dirac point and an opening of a band gap due to the…

介观与纳米尺度物理 · 物理学 2010-01-23 A. Deshpande , W. Bao , Z. Zhao , C. N. Lau , B. J. LeRoy

Memory or transistor devices based on electron's spin rather than its charge degree of freedom offer certain distinct advantages and comprise a cornerstone of spintronics. Recent years have witnessed the emergence of a new field,…

介观与纳米尺度物理 · 物理学 2021-09-13 Md. S. Hossain , M. K. Ma , K. A. Villegas Rosales , Y. J. Chung , L. N. Pfeiffer , K. W. West , K. W. Baldwin , M. Shayegan

Freestanding photonic crystals can be used to trap both light and mechanical vibrations. These "optomechanical crystal" structures have already been experimentally demonstrated to yield strong coupling between a photon mode and a phonon…

光学 · 物理学 2013-12-03 Michael Schmidt , Vittorio Peano , Florian Marquardt

We study theoretically interaction of a bilayer graphene with a circularly polarized ultrafast optical pulse of a single oscillation at an oblique incidence. The normal component of the pulse breaks the inversion symmetry of the system and…

介观与纳米尺度物理 · 物理学 2021-11-10 Pardeep Kumar , Thakshila M. Herath , Vadym Apalkov

A valley filter capable of generating a valley-polarized current is a crucial element in valleytronics, yet its implementation remains challenging. Here, we propose a valley filter made of a graphene bilayer which exhibits a 1D moir\'{e}…

介观与纳米尺度物理 · 物理学 2024-04-19 Kai Shao , Hao Geng , Erfu Liu , Jose L. Lado , Wei Chen , D. Y. Xing

We develop a microscopic theory of an unconventional photogalvanic effect in two-dimensional materials with the Dirac energy spectrum of the carriers of charge under strong driving. As a test bed, we consider a layer of a transition metal…

介观与纳米尺度物理 · 物理学 2019-02-13 V. M. Kovalev , I. G. Savenko

Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize…

We study massive Dirac fermion tunneling through time periodic potential in a silicene-based N-TP-N junction, where Ns are normal silicene regions and TP is the time periodic potential barrier. The fermions would absorb or emit photons due…

介观与纳米尺度物理 · 物理学 2020-02-06 Ruanglak Jongchotinon , Bumned Soodchomshom

Electron wavefunctions in twisted bilayer graphene may have a strong single layer character or be intrinsically delocalized between layers, with their nature often determined by how energetically close they are to the Dirac point. In this…

介观与纳米尺度物理 · 物理学 2014-10-06 Chi-Ken Lu , H. A. Fertig

Guided by the analogy to Mie scattering of light on small particles we show that the propagation of a Dirac-electron wave in graphene can be manipulated by a circular gated region acting as a quatum dot. Large dots enable electron lensing,…

介观与纳米尺度物理 · 物理学 2015-06-12 R. L. Heinisch , F. X. Bronold , H. Fehske

We study the optical properties of semiconducting transition metal dichalcogenide monolayers under the influence of strong out-of-plane magnetic fields, using the effective massive Dirac model. We pay attention to the role of spin-orbit…

介观与纳米尺度物理 · 物理学 2019-03-14 G. Catarina , J. Have , J. Fernández-Rossier , N. M. R. Peres

Manipulating the circular polarization of light is of great importance in chemistry and biology, as chiral molecules exhibit different physiological properties when exposed to different circularly polarized waves. Here we suggest a…

光学 · 物理学 2023-07-19 Tuo Chen , Sailing He