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Related papers: Valley polarization braiding in strained graphene

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The valley splitting, which lifts the degeneracy of the lowest two valley states in a SiO$_2$/(100)Si/SiO$_2$ quantum well is examined through transport measurements. We demonstrate that the valley splitting can be observed directly as a…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 K. Takashina , Y. Ono , A. Fujiwara , Y. Takahashi , Y. Hirayama

Physical properties reflecting valley asymmetry of Landau levels in a biased bilayer graphene under magnetic field are discussed. Within the $4-$band continuum model with Hartree-corrected self-consistent gap and finite damping factor we…

Mesoscale and Nanoscale Physics · Physics 2010-01-14 Masaaki Nakamura , Eduardo V. Castro , Balazs Dora

We theoretically study the correlated insulator states, quantum anomalous Hall (QAH) states, and field-induced topological transitions between different correlated states in twisted multilayer graphene systems. Taking twisted…

Mesoscale and Nanoscale Physics · Physics 2022-06-02 Shihao Zhang , Xi Dai , Jianpeng Liu

The rise of graphene opens a new door to qubit implementation, as discussed in the recent proposal of valley pair qubits in double quantum dots of gapped graphene (Wu et al., arXiv: 1104.0443 [cond-mat.mes-hall]). The work here presents the…

Mesoscale and Nanoscale Physics · Physics 2011-07-05 G. Y. Wu , N. -Y. Lue , L. Chang

In graphene, the valleys represent spin-like quantities and can act as a physical resource in valley-based electronics to novel quantum computation schemes. Here we demonstrate a direct route to tune and read the valley quantum states of…

Mesoscale and Nanoscale Physics · Physics 2012-06-19 Atindra Nath Pal , Vidya Kochat , Arindam Ghosh

Monolayer Graphene contains two inequivalent local minimum, valleys, located at $K$ and $K'$ in the Brillouin zone. There has been considerable interest in the use of these two valleys as a doublet for information processing. Herein I…

Mesoscale and Nanoscale Physics · Physics 2020-06-02 Samuel Bladwell

We have experimentally investigated the hole states in a gated vertical strained Si/SiGe quantum dot. We demonstrate the inhomogeneous strain relaxation on the lateral surface creates a ring-like potential near the perimeter of the dot,…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Jun Liu , A. Zaslavsky , L. B. Freund

We demonstrate the existence of localized states in close vicinity of a linear defect in graphene. These states have insulating or conducting character. Insulating states form a flat band, while conducting states present a slowdown of the…

Mesoscale and Nanoscale Physics · Physics 2020-06-03 Francesco Romeo

We introduce a novel two-dimensional electronic system with ultrastrong interlayer interactions, namely twisted bilayer graphene with a large twist angle, as an ideal ground for realizing interlayer-coherent excitonic condensates. In these…

Mesoscale and Nanoscale Physics · Physics 2022-12-20 Dohun Kim , Byungmin Kang , Yong-Bin Choi , Kenji Watanabe , Takashi Taniguchi , Gil-Ho Lee , Gil Young Cho , Youngwook Kim

We describe the formation of superconducting states in graphene in the presence of pseudo-Landau levels induced by strain, when time reversal symmetry is preserved. We show that superconductivity in strained graphene is quantum critical…

Superconductivity · Physics 2013-07-29 Bruno Uchoa , Yafis Barlas

We propose a model of spin-polarized-current state for electrons in bilayer graphene. The model resolves the puzzles as revealed by experiments that (a) the energy gap $E_{\rm gap}$ of the insulating ground state at the charge neutrality…

Strongly Correlated Electrons · Physics 2014-05-14 Xin-Zhong Yan , C. S. Ting

Valley-polarized quantum Hall states in graphene are described by a Heisenberg O(3) ferromagnet model, with the ordering type controlled by the strength and sign of valley anisotropy. A mechanism resulting from electron coupling to…

Mesoscale and Nanoscale Physics · Physics 2008-04-14 Dmitry A. Abanin , Patrick A. Lee , Leonid S. Levitov

Bilayer graphene, in the presence of a one-sided spin-orbit interaction (SOI) induced by a suitably chosen substrate, is predicted to exhibit unconventional Quantum Hall states. The new states arise due to strong SOI-induced splittings of…

Mesoscale and Nanoscale Physics · Physics 2018-12-07 Jun Yong Khoo , Leonid Levitov

Electrons in graphene have fourfold spin and valley degeneracies owing to the unique bipartite honeycomb lattice and an extremely weak spin-orbit coupling, which can support a series of broken symmetry states. Atomic-scale defects in…

Mesoscale and Nanoscale Physics · Physics 2022-08-17 Yu Zhang , Liangguang Jia , Yaoyao Chen , Lin He , Yeliang Wang

We report on ground- and excited state transport through an electrostatically defined few-hole quantum dot in bilayer graphene in both parallel and perpendicular applied magnetic fields. A remarkably clear level scheme for the two-particle…

Mesoscale and Nanoscale Physics · Physics 2019-07-17 A. Kurzmann , M. Eich , H. Overweg , M. Mangold , F. Herman , P. Rickhaus , R. Pisoni , Y. Lee , R. Garreis , C. Tong , K. Watanabe , T. Taniguchi , K. Ensslin , T. Ihn

The electronic structure of bilayer graphene under pressure develops very interesting features with an enhancement of the trigonal warping and a splitting of the parabolic touching bands at the K point of the reciprocal space into four…

Materials Science · Physics 2016-07-06 F Munoz , H. P. Ojeda Collado , Gonzalo Usaj , Jorge O. Sofo , C. A. Balseiro

We report the existence of zero energy surface states localized at zigzag edges of bilayer graphene. Working within the tight-binding approximation we derive the analytic solution for the wavefunctions of these peculiar surface states. It…

Mesoscale and Nanoscale Physics · Physics 2008-01-16 Eduardo V. Castro , N. M. R. Peres , J. M. B. Lopes dos Santos , A. H. Castro Neto , F. Guinea

At high magnetic fields the conductance of graphene is governed by the half-integer quantum Hall effect. By local electrostatic gating a \textit{p-n} junction perpendicular to the graphene edges can be formed, along which quantum Hall…

We report on the emergence of bulk, valley-polarized currents in graphene-based devices, driven by spatially varying regions of broken sublattice symmetry, and revealed by non-local resistance ($R_\mathrm{NL}$) fingerprints. By using a…

Mesoscale and Nanoscale Physics · Physics 2021-03-10 Thomas Aktor , Jose H. Garcia , Stephan Roche , Antti-Pekka Jauho , Stephen R. Power

In a Bernal-stacked graphene bilayer, an electronic state in Landau level $% N=0$ is described by its guiding-center index $X$ (in the Landau gauge) and by its valley, spin, and orbital indices $\xi =\pm K,\sigma =\pm 1,$ and $% n=0,1.$…

Mesoscale and Nanoscale Physics · Physics 2014-01-08 J. Lambert , R. Côté