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Related papers: Valley-selective Floquet Chern Flat Bands in Twist…

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We derive the angular generation density of photoexcited carriers in gapless and gapped Bernal bilayer graphene. Exploiting the strong anisotropy of the band structure of bilayer graphene at low energies due to trigonal warping, we show…

Mesoscale and Nanoscale Physics · Physics 2024-09-16 T. J. Osborne , M. E. Portnoi , E. Mariani

We report on the effect of laser illumination with circularly polarized light on the electronic structure of AB-stacked graphite samples. By using Floquet theory in combination with Green's function techniques, we find that the polarized…

Mesoscale and Nanoscale Physics · Physics 2020-02-20 Hernan L. Calvo , Jose E. Barrios Vargas , Luis E. F. Foa Torres

We derive effective Floquet Hamiltonians for twisted bilayer graphene driven by circularly polarized light in two different regimes beyond the weak-drive, high frequency regime. First, we consider a driving protocol relevant for experiments…

Mesoscale and Nanoscale Physics · Physics 2020-07-01 Michael Vogl , Martin Rodriguez-Vega , Gregory A. Fiete

The valley dependent optical selection rules in recently discovered monolayer group-VI transition metal dichalcogenides (TMDs) make possible optical control of valley polarization, a crucial step towards valleytronic applications. However,…

Mesoscale and Nanoscale Physics · Physics 2014-07-31 Rui-Lin Chu , Xiao Li , Sanfeng Wu , Qian Niu , Wang Yao , Xiaodong Xu , Chuanwei Zhang

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

We show that rhombohedral multilayer graphene supports topological frequency conversion, whereby a fraction of electrons transfer energy between two monochromatic light sources at a quantized rate. The pristine nature and gate tunability of…

Mesoscale and Nanoscale Physics · Physics 2024-10-25 Étienne Lantagne-Hurtubise , Iliya Esin , Gil Refael , Frederik Nathan

Twisted bilayer graphene aligned with hexagonal boron nitride (TBG/hBN) hosts rich topological and correlated quantum phases, such as (fractional) Chern insulators, whose character is dictated by the topology of the moir\'{e} flat band.…

Strongly Correlated Electrons · Physics 2026-05-01 Huiwen Wang , Wei Jiang

Rhombohedral multilayer graphene, with its flat electronic bands and concentrated Berry curvature, is a promising material for the realization of correlated topological phases of matter. When aligned to an adjacent hexagonal boron nitride…

Mesoscale and Nanoscale Physics · Physics 2025-09-16 Samuel H. Aronson , Tonghang Han , Zhengguang Lu , Yuxuan Yao , Kenji Watanabe , Takashi Taniguchi , Long Ju , Raymond C. Ashoori

Trilayer graphene (TLG) exhibits rich novel electronic properties and extraordinary quantum Hall phenomena owning to enhanced electronic interactions and tunable chirality of its quasiparticles. Here, we report direct observation of…

Materials Science · Physics 2017-02-15 Long-Jing Yin , Wen-Xiao Wang , Yu Zhang , Yang-Yang Ou , Hao-Ting Zhang , Cai-Yun Shen , Lin He

Motivated by the higher Chern bands of twisted graphene multilayers, we consider flat bands with arbitrary Chern number $C$ with ideal quantum geometry. While $C>1$ bands differ from Landau levels, we show that these bands host exact…

Mesoscale and Nanoscale Physics · Physics 2023-07-25 Junkai Dong , Patrick J. Ledwith , Eslam Khalaf , Jong Yeon Lee , Ashvin Vishwanath

Twisted graphene bilayers provide a versatile platform to engineer metamaterials with novel emergent properties by exploiting the resulting geometric moir\'{e} superlattice. Such superlattices are known to host bulk valley currents at tiny…

Mesoscale and Nanoscale Physics · Physics 2019-09-04 T. M. R. Wolf , J. L. Lado , G. Blatter , O. Zilberberg

Recent experiments have observed possible spin- and valley-polarized insulators and spin-triplet superconductivity in twisted double bilayer graphene, a moire structure consisting of a pair of Bernal-stacked bilayer graphene. Besides the…

Strongly Correlated Electrons · Physics 2020-08-12 Yi-Ting Hsu , Fengcheng Wu , S. Das Sarma

Ultraflat bands have already been detected in twisted bilayer graphene and twisted bilayer transition-metal dichalcogenides, which provide a platform to investigate strong correlations. In this paper, the electronic properties of twisted…

Materials Science · Physics 2024-03-05 Yonggang Li , Zhen Zhan , Shengjun Yuan

Recent advances in the field of condensed-matter physics have unlocked the potential to realize and control emergent material phases that do not exist in thermal equilibrium. One of the most promising concepts in this regard is Floquet…

Twisted bilayer graphene (TBG) is a recently discovered two-dimensional superlattice structure which exhibits strongly-correlated quantum many-body physics, including strange metallic behavior and unconventional superconductivity. Most of…

Mesoscale and Nanoscale Physics · Physics 2024-04-22 Cunyuan Jiang , Matteo Baggioli , Qing-Dong Jiang

Bloch states of electrons in honeycomb two-dimensional crystals with multi-valley band structure and broken inversion symmetry have orbital magnetic moments of a topological nature. In crystals with two degenerate valleys, a perpendicular…

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…

Mesoscale and Nanoscale Physics · Physics 2024-11-26 Ceren B. Dag , Vasil Rokaj

Twisted bilayer graphene displays many fascinating properties that can be tuned by varying the relative angle (also called twist angle) between its monolayers. As a remarkable feature, both the electronic flat bands and the corresponding…

Materials Science · Physics 2022-05-06 V. Hung Nguyen , Trinh X. Hoang , J. -C. Charlier

In this Letter, both the manipulation of valley-polarized currents and the optical-like behaviors of Dirac fermions are theoretically explored in polycrystalline graphene. When strain is applied, the misorientation between two graphene…

Mesoscale and Nanoscale Physics · Physics 2016-12-14 Viet Hung Nguyen , Samuel Dechamps , Philippe Dollfus , Jean-Christophe Charlier

The valley degeneracy of electron states in graphene stimulates intensive research of valley-related optical and transport phenomena. While many proposals on how to manipulate valley states have been put forward, experimental access to the…

Mesoscale and Nanoscale Physics · Physics 2014-11-17 L. E. Golub , S. A. Tarasenko