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Related papers: Light-Induced Valleytronics in Pristine Graphene

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Valleytronics is rapidly emerging as an exciting area of basic and applied research. In two dimensional systems, valley polarisation can dramatically modify physical properties through electron-electron interactions as demonstrated by such…

We describe an angularly asymmetric interface-scattering mechanism which allows to spatially separate the electrons in the two low-energy valleys of bilayer graphene. The effect occurs at electrostatically defined interfaces separating…

Mesoscale and Nanoscale Physics · Physics 2010-11-05 Henning Schomerus

This work performs a numerical study of electron transport through the fundamental logic gate in valleytronics - a valley valve consisting of two or increasing number of valley filters. Various typical effects on the transport are…

Mesoscale and Nanoscale Physics · Physics 2022-11-09 Jia-Huei Jiang , Ning-Yuan Lue , Feng-Wu Chen , Yu-Shu G. Wu

Electrons in graphene, in addition to their spin, have two pseudospin degrees of freedom: sublattice and valley pseudospin. Valleytronics uses the valley degree of freedom as a carrier of information similar to the way spintronics uses…

Mesoscale and Nanoscale Physics · Physics 2013-04-03 D. Moldovan , M. Ramezani Masir , L. Covaci , F. M. Peeters

Graphene is a two-dimensional carbon material with a honeycomb lattice and Dirac-type low-energy spectrum. In a strong magnetic field, where Coulomb interactions dominate against disorder broadening, quantum Hall ferromagnetic states…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Naokazu Shibata , Kentaro Nomura

A two-dimensional electron system placed in a magnetic field develops Landau levels, where strong Coulomb interactions lead to the appearance of many-body correlated ground states. Quantum numbers similar to the electron spin enable the…

Mesoscale and Nanoscale Physics · Physics 2023-08-14 Ke Huang , Hailong Fu , Danielle Reifsnyder Hickey , Nasim Alem , Xi Lin , Kenji Watanabe , Takashi Taniguchi , Jun Zhu

Monolayer graphene is an example of materials with multi-valley electronic structure. In such materials, the valley index is being considered as an information carrier. Consequently, relaxation mechanisms leading to loss of valley…

Mesoscale and Nanoscale Physics · Physics 2015-08-28 Péter Boross , András Pályi

Nonlinear second harmonic optical activity of graphene covering a gold photon sieve was determined for different polarizations. The photon sieve consists of a subwavelength gold nanohole array placed on glass. It combines the benefits of…

Mesoscale and Nanoscale Physics · Physics 2016-01-14 Michael Lobet , Michael Sarrazin , Francesca Cecchet , Nicolas Reckinger , Alexandru Vlad , Jean-François Colomer , Dan Lis

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…

Mesoscale and Nanoscale Physics · Physics 2021-11-10 Pardeep Kumar , Thakshila M. Herath , Vadym Apalkov

Modulation of electronic states in two-dimensional (2D) materials can be achieved by using in-plane variations of the band gap or the average potential in lateral quantum structures. In the atomic configurations with hexagonal symmetry,…

Mesoscale and Nanoscale Physics · Physics 2016-08-10 Feng-Wu Chen , Mei-Yin Chou , Yiing-Rei Chen , Yu-Shu Wu

We discuss valley current, which is carried by quasiparticles in graphene. We show that the valley current arises owing to a peculiar term in the electron-phonon collision integral that mixes the scalar and vector gauge-field-like vertices…

Mesoscale and Nanoscale Physics · Physics 2023-05-10 Ankang Liu , Alexander M. Finkel'stein

Valley is a useful degree of freedom for non-dissipative electronics since valley current that can flow even in an insulating material does not accompany electronic current. We use dual-gated bilayer graphene in the Hall bar geometry to…

Mesoscale and Nanoscale Physics · Physics 2016-01-20 Yuya Shimazaki , Michihisa Yamamoto , Ivan V. Borzenets , Kenji Watanabe , Takashi Taniguchi , Seigo Tarucha

The unique optical properties of graphene, with broadband absorption and ultrafast response, make it a critical component of optoelectronic and spintronic devices. Using time-resolved momentum microscopy with high data rate and high dynamic…

The concept of valleytronics has recently gained considerable research attention due to its intriguing physical phenomena and practical applications in optoelectronics and quantum information. In this study, by employing GW-BSE calculations…

Materials Science · Physics 2024-01-22 Vo Khuong Dien , Pham Thi Bich Thao , Nguyen Thi Han , Nguyen Thanh Tien

Transition metal dichalcogenide semiconductors represent elementary components of layered heterostructures for emergent technologies beyond conventional opto-electronics. In their monolayer form they host electrons with quantized circular…

Recent advances in condensed matter physics have shown that the valley degree of freedom of electrons in 2D materials with hexagonal symmetry, such as graphene, h-BN, and TMDs, can be efficiently exploited, leading to the emergent field of…

Optics · Physics 2018-11-02 S. Guddala , R. Bushati , M. Li , A. B. Khanikaev , V. M. Menon

Single-layer and Bilayer of graphene are new classes of two-dimensional electron systems with unconventional band structures and valley degrees of freedom. The ground states and excitations in the integer and fractional quantum Hall regimes…

Strongly Correlated Electrons · Physics 2015-05-13 Naokazu Shibata , Kentaro Nomura

The achievement of valley-polarized electron currents is a cornerstone for the realization of valleytronic devices. Here, we report on ballistic coherent transport experiments where two opposite quantum point contacts (QPCs) are defined by…

In crystals, energy band extrema in momentum space can be identified by their valley index. The internal quantum degree of freedom associated with valley pseudospin indices can act as a useful information carrier analogous to electronic…

A population imbalance at different valleys of an electronic system lowers its effective rotational symmetry. We introduce a technique to measure such imbalance - a valley polarization - that exploits the unique fingerprints of this…