<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>B</mml:mi><mml:mo stretchy="false">→</mml:mo><mml:msub><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mi>π</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>K</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math>decays in the perturbative QCD approach

Zhang, Zhiqing; Hou, Zhi-Wei; Yang, Yueling; Sun, J. F.

doi:10.1103/physrevd.90.074023

Cited by 10 publications

(16 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In more extended configurations, similar observations have been reported on multiple fold structures [18,19] with preliminary evidence of valley polarized states. These studies are supported by previous work on extended deformations predicting valley polarized edge-like states at the strain region, which acts as a waveguide focusing electron currents [1][2][3][4][5]. These are all promising structures for potential device applications.…”

supporting

confidence: 70%

“…We identify precise conditions for new conducting edges-like states to be valley polarized, with the flexibility of positioning them at chosen locations in the system. A map of local density of states as a function of energy and position reveals a unique braid pattern that serves as a fingerprint to identify valley polarization.Strained graphene has emerged as an important tool to implement valleytronic based devices, and in particular, in protocols for quantum computation [1][2][3][4][5][6][7][8][9][10][11][12]. Recent experimental developments show that substrate engineering can be used to design deformation geometries with specific strain profiles [13][14][15][16][17][18][19][20][21][22][23].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Valley polarization braiding in strained graphene

et al. 2020

View full text Add to dashboard Cite

Previous works on deformed graphene predict the existence of valley-polarized states, however, optimal conditions for their detection remain challenging. We show that in the quantum Hall regime, edge-like states in strained regions can be isolated in energy within Landau gaps. We identify precise conditions for new conducting edges-like states to be valley polarized, with the flexibility of positioning them at chosen locations in the system. A map of local density of states as a function of energy and position reveals a unique braid pattern that serves as a fingerprint to identify valley polarization.Strained graphene has emerged as an important tool to implement valleytronic based devices, and in particular, in protocols for quantum computation [1][2][3][4][5][6][7][8][9][10][11][12]. Recent experimental developments show that substrate engineering can be used to design deformation geometries with specific strain profiles [13][14][15][16][17][18][19][20][21][22][23]. Clear signatures of valley splitting in confined geometries represent an important step in this direction, as exemplified by STM studies on graphene quantum dots [24]. In more extended configurations, similar observations have been reported on multiple fold structures [18,19] with preliminary evidence of valley polarized states. These studies are supported by previous work on extended deformations predicting valley polarized edge-like states at the strain region, which acts as a waveguide focusing electron currents [1][2][3][4][5]. These are all promising structures for potential device applications. However, several drawbacks are still present because optimal conditions for creation and detection of valley split currents are not well-defined.To take advantage of the existence of valley polarized channels, usually embedded in graphene's conducting background, it is crucial to separate their contribution from other extended states. We show that this can be achieved by introducing an external magnetic field large enough to take the system into the Quantum Hall regime. Such a configuration conveniently allows the isolation of the valley polarized edge states in energy and in real space. As we show below, it is possible to design configurations within available experimental capabilities to produce valley polarized currents for a wide energy range within Landau gaps. Moreover, the flexibility to place the deformation at different parts of the sample provides a wider versatility of contact probes to identify and collect these currents.We present local density of states (LDOS) results for a model of graphene with a fold-like deformation that predict valley split peaks that could be measured in STM experiments. As the deformed region is traversed across, maximum LDOS intensities for each valley evolve in en-ergy, leading to a braid structure that serves as a unique fingerprint of valley polarized states. Under bias, these states generate new extra conducting channels that can be visualized as new edge states created along the deformation region.In order to ...

show abstract

supporting

confidence: 70%

mentioning

confidence: 99%

Valley polarization braiding in strained graphene

et al. 2020

View full text Add to dashboard Cite

show abstract

“…For other phenomenological studies of (axial-)vector mesons (with emphasis on the mixing between the K 1;A and the K 1;B states), see Refs. [38][39][40][41][42].…”

Section: Homochiral Vectorsmentioning

confidence: 99%

How the axial anomaly controls flavor mixing among mesons

2018

View full text Add to dashboard Cite

It is well known that, because of the axial anomaly in QCD, mesons with J P ¼ 0 − are close to SUð3Þ V eigenstates; the η 0 ð958Þ meson is largely a singlet, and the η meson an octet. In contrast, states with J P ¼ 1 − are flavor diagonal; e.g., the ϕð1020Þ is almost puress. Using effective Lagrangians, we show how this generalizes to states with higher spin, assuming that they can be classified according to the unbroken chiral symmetry of G fl ¼ SUð3Þ L × SUð3Þ R . We construct effective Lagrangians from terms invariant under G fl and introduce the concept of hetero-and homochiral multiplets. Because of the axial anomaly, only terms invariant under the Zð3Þ A subgroup of the axial Uð1Þ A enter. For heterochiral multiplets, which begin with that including the η and η 0 ð958Þ, there are Zð3Þ A invariant terms with low mass dimension which cause states to mix according to SUð3Þ V flavor. For homochiral multiplets, which begin with that including the ϕð1020Þ, there are no Zð3Þ A invariant terms with low mass dimension, and so states are diagonal in flavor.In this way, we predict the flavor mixing for the heterochiral multiplet with spin 1 as well as for hetero-and homochiral multiplets with spin 2 and spin 3.

show abstract

“…For 3D materials, Table 2 lists the calculated ideal tensile and shear strengths via affine pure deformation of a broad class of materials with different symmetry except triclinic system, together with the previous theoretical values [4,7,27,[49][50][51][52][53] for comparison. It is found that all calculated values by ADAIS code are in reasonable agreement with the previous theoretical values [4,7,27,[49][50][51][52][53], confirming the validity of ADAIS code for 3D materials. Also, Table 3 lists the calculated uniaxial and biaxial tensile strengths of 2D materials with hexagonal and rectangular systems, together with the previous theoretical values [23,54] for comparison.…”

Section: Ideal Tensile and Shear Strengths By Affine Deformationmentioning

confidence: 99%

“…ultraincompressible and hard materials, has recently attracted tremendous interest because of their fundamental importance in material science/physics and also their technological applications such as cutting and polishing tools in machinery industry, and drilling bits in milling and petrochemical industry [1][2][3]. Because of its high efficiency and low cost, high-throughput (HT) first-principles computations are becoming one of the most promising and impressive solutions to search the novel strong solids, most of which adopt the energy [4][5][6], elastic moduli [7] or empirical rules [8,9] as descriptors. However, these descriptors do not always guarantee a high mechanical strength, due to their indirect correlation to the crystal plasticity, i.e.…”

Section: Introductionmentioning

confidence: 99%

ADAIS: Automatic Derivation of Anisotropic Ideal Strength via high-throughput first-principles computations

Zhang

2019

Computer Physics Communications

View full text Add to dashboard Cite

Anisotropic ideal strength is a fundamental and important plasticity parameter in scaling the intrinsic strength of strong crystalline materials, and is a potential descriptor in searching and designing novel hard/superhard materials. However, to the best of our knowledge, an automatic derivation of anisotropic ideal strength has not been implemented in any open-source code available so far. In this paper, we present our developed ADAIS code, an automatic derivation of anisotropic ideal strength via high-throughput first-principles computations for both three-dimensional and two-dimensional crystalline materials with any symmetry, as well as for an ideal interface model. Several fundamental mechanical quantities can be automatically derived, including ideal tensile and shear strengths through affine deformation, universal binding energy and generalized stacking fault energy, as well as the ideal cleavage and slide stresses through alias deformation. The implementation of this code has been comprehensively demonstrated and critically validated by a lot of evaluations and tests of various crystalline materials with different symmetry, indicating that our code could provide a high-efficiency solution to quantify the strength of strong solids. Generalized stacking fault energy 3 Program summary Program title: ADAIS Licensing provisions: BSD 3-Clause Programming language: Fortran90 Nature of problem: A scheme adapted to high-throughput first-principles computations is much necessary to automatically determine the anisotropic ideal strength along any crystallographic orientation under affine and alias deformations for crystalline solids with any symmetry.Solution method: To derive the ideal strength of a crystalline solid along a specific crystallographic orientation, a projection and/or redefinition of a lattice are firstly performed.The affine (alias) deformation is then applied to the projected (redefined) lattice, and a relaxation is done on the distorted structure by the simply modified VASP code optimizer with certain cell constraints. Afterwards, the resultant total energies and stresses vs strain are generated accordingly. Finally, the anisotropic ideal strengths are derived from the calculated stress/energy-strain relationship, and meanwhile the variation of bond length as a function of strain is revealed to illustrate the failure mode. Whenever an unexpected error happens, a message will be printed for further evaluation.

show abstract

B→K1π(K)decays in the perturbative QCD approach

Abstract: Within the framework of the perturbative QCD approach, we study the two

Cited by 10 publications

References 50 publications

Valley polarization braiding in strained graphene

Valley polarization braiding in strained graphene

How the axial anomaly controls flavor mixing among mesons

ADAIS: Automatic Derivation of Anisotropic Ideal Strength via high-throughput first-principles computations

Contact Info

Product

Resources

About