This paper mainly deals with the point groups and single forms of octagonal quasicrystals and the description of one-dimensional quasilattice. The authors present a new sequence for describing the arrangement of quasi...This paper mainly deals with the point groups and single forms of octagonal quasicrystals and the description of one-dimensional quasilattice. The authors present a new sequence for describing the arrangement of quasiperiods in one-dimensional quasilattice. The first ten numbers of quasiperiods of this sequence are 1, 1, 2, 5, 12, 29, 70, 169, 408 and 985. The arrangement of quasiperiods in the first five steps are a, b, ab. babab and babababbabab. Seven p(?)nt groups and nine single forms for the octagonal system have been deduced, They are as follows: Point groups: 8.8m, 82, 8/m, 8/mmm, 8 and 82m; single forms: octagonal prism, dioctagonal prism. octagonal pyramid. dioctagonal pyramid. octagonal dipyramid, dioctagonal dipyramid, octagonal scalenohedron, dioctagonal scalenohedron and octagonal trapezohedron. Besides seven point groups and nine single forms for the dodecahegonal system have also been deduced.展开更多
Wang N. et al. reported the discovery of a new type of two-dimensional quasicrystal with eightfold symmetry in rapidly solidified Cr<sub>5</sub>Ni<sub>3</sub>Si<sub>2</sub> and V<...Wang N. et al. reported the discovery of a new type of two-dimensional quasicrystal with eightfold symmetry in rapidly solidified Cr<sub>5</sub>Ni<sub>3</sub>Si<sub>2</sub> and V<sub>15</sub>Ni<sub>10</sub>Si alloys. Many authors studied the electron diffraction pattern of eightfold symmetry quasicrystal and obtained some Penrose graphs with eightfold rotational symmetry. A fractal展开更多
Unconventional fermions in the immensely studied topological semimetals are the source for rich exotic topological properties.Here,using symmetry analysis and first-principles calculations,we propose the coexistence o...Unconventional fermions in the immensely studied topological semimetals are the source for rich exotic topological properties.Here,using symmetry analysis and first-principles calculations,we propose the coexistence of multiple topological nodal structure in LaSb_(2),including topological nodal surfaces,nodal lines and in particular eightfold degenerate nodal points,which have been scarcely observed in a single material.Further,utilizing angle-resolved photoemission spectroscopy,we confirm the existence of nodal surfaces and eightfold degenerate nodal points in LaSb_(2).The intriguing multiple topological nodal structure might play a crucial role in giving rise to the large linear magnetoresistance.Our work renews the insights into the exotic topological phenomena in LaSb_(2).展开更多
文摘This paper mainly deals with the point groups and single forms of octagonal quasicrystals and the description of one-dimensional quasilattice. The authors present a new sequence for describing the arrangement of quasiperiods in one-dimensional quasilattice. The first ten numbers of quasiperiods of this sequence are 1, 1, 2, 5, 12, 29, 70, 169, 408 and 985. The arrangement of quasiperiods in the first five steps are a, b, ab. babab and babababbabab. Seven p(?)nt groups and nine single forms for the octagonal system have been deduced, They are as follows: Point groups: 8.8m, 82, 8/m, 8/mmm, 8 and 82m; single forms: octagonal prism, dioctagonal prism. octagonal pyramid. dioctagonal pyramid. octagonal dipyramid, dioctagonal dipyramid, octagonal scalenohedron, dioctagonal scalenohedron and octagonal trapezohedron. Besides seven point groups and nine single forms for the dodecahegonal system have also been deduced.
文摘Wang N. et al. reported the discovery of a new type of two-dimensional quasicrystal with eightfold symmetry in rapidly solidified Cr<sub>5</sub>Ni<sub>3</sub>Si<sub>2</sub> and V<sub>15</sub>Ni<sub>10</sub>Si alloys. Many authors studied the electron diffraction pattern of eightfold symmetry quasicrystal and obtained some Penrose graphs with eightfold rotational symmetry. A fractal
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406304)the National Natural Science Foundation of China(Grant Nos.U2032208,12222413,11874264,12074181,11834006,and 12104217)+9 种基金the Natural Science Foundation of Shanghai(Grant Nos.23ZR1482200,22ZR1473300,and 14ZR1447600)the Shanghai Science and Technology Innovation Action Plan(Grant No.21JC1402000)the Open Projects from State Key Laboratory of Functional Materials for Informatics(Grant No.SKL2022)the Double First-Class Initiative Fund of Shanghai Tech Universitythe fund of Science and Technology on Surface Physics and Chemistry Laboratory(Grant No.6142A02200102)supported by ME2Project(Grant No.11227902)from the National Natural Science Foundation of Chinasupported by the National Key Projects for Research and Development of China(Grant No.2021YFA1400400)the Fundamental Research Funds for the Central Universities(Grant No.020414380185)the Natural Science Foundation of Jiangsu Province(Grant No.BK20200007)the Fok Ying-Tong Education Foundation of China(Grant No.161006)。
文摘Unconventional fermions in the immensely studied topological semimetals are the source for rich exotic topological properties.Here,using symmetry analysis and first-principles calculations,we propose the coexistence of multiple topological nodal structure in LaSb_(2),including topological nodal surfaces,nodal lines and in particular eightfold degenerate nodal points,which have been scarcely observed in a single material.Further,utilizing angle-resolved photoemission spectroscopy,we confirm the existence of nodal surfaces and eightfold degenerate nodal points in LaSb_(2).The intriguing multiple topological nodal structure might play a crucial role in giving rise to the large linear magnetoresistance.Our work renews the insights into the exotic topological phenomena in LaSb_(2).
