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Peierls-phase-induced topological semimetals in an optical lattice:Moving of Dirac points,anisotropy of Dirac cones,and hidden symmetry protection

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Chinese Physics B 2020年第12期29卷 82-87页

作者： Jing-Min Hou School of Physics Southeast UniversityNanjing 211189China

We propose a square optical lattice in which some of neighbor hoppings have a Peierls *** Peierls phase makes the lattice have a special band structure and induces the existence of Dirac points in the Brillouin zone,which means that topological semimetals exist in the *** Dirac points move with the change of the Peierls phase and the Dirac cones are anisotropic for some vales of the Peierls *** lattice has a novel hidden symmetry,which is a composite antiunitary symmetry composed of a translation operation,a sublattice exchange,a complex conjugation,and a local U(1)gauge *** prove that the Dirac points are protected by the hidden symmetry and perfectly explain the moving of Dirac points with the change of the Peierls phase based on the hidden symmetry protection.

关键词： topological semimetal optical lattice hidden symmetry

hidden antiunitary symmetry behind ＂accidental＂ degeneracy and its protection of degeneracy

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Frontiers of physics 2018年第1期13卷 211-214页

作者： Jing-Min Hou Wei Chen School of Physics Southeast University Nanjing 211189 China College of Science Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

In quantum mechanics, accidental degeneracy refers to energy degeneracy that occurs coincidentally, without any protection by symmetry. Here, we prove a theorem stating that any two-fold degeneracy （accidental or not） in a quantum system is protected by a novel hidden symmetry, which can be expressed by an antiunitary operator with its square being -1. In this sense, the so-called accidental degeneracy is not really accidental, and this actually implies a hidden antiunitary symmetry.

关键词： accidental degeneracy hidden symmetry antiunitary symmetry

Nuclear axial currents from scale-chiral effective field theory

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Chinese Physics C 2018年第9期42卷 96-101页

作者： Yan-Ling Li Yong-Liang Ma Mannque Rho Center for Theoretical Physics and College of Physics Jilin UniversityChangchun 130012China Institut de Physique Theorique CEA Saclay91191 Oif-sur-Yvette cedexFrance

By incorporating hidden scale symmetry and hidden local symmetry in the nuclear effective field theory,combined with the double soft-pion theorem, we predict that the Gamow-Teller operator coming from the space component of the axial current should remain unaffected by the QCD vacuum change caused by the baryonic density,whereas the first forbidden beta transition operator coming from the time component should be strongly *** the latter has been confirmed for some time, the former was given support by a powerful recent ab initio quantum Monte Carlo calculation for light nuclei, which also confirmed the old？chiral filter hypothesis.＂ Formulated in terms of the Fermi-liquid fixed point structure of strong-coupled nuclear interactions, we offer an extremely simple resolution to the long-standing puzzle of the＂quenched g A,＂ gAeff ≈1 [1], found in nuclear Gamow-Teller beta transitions, giant Gamow-Teller resonances, and double beta decays.

关键词： effective field theory hidden symmetry fermi-liquid fixed point quenched gA

Hodge Dual symmetry of Green-Schwarz Superstring in AdS_5S^5

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Communications in Theoretical Physics 2008年第6期49卷 1573-1576页

作者： XIONG Chuan-Hua Institute of Modern Physics Northwest University Xi＇an 710069 China Department of Modern Physics University of Science and Technology of China Hefei 230026 China

The hidden symmetry and an infinite set non-local conserved currents of the Green-Schwarz superstring on AdS549 S^5 have been pointed out by Bena et al. In this paper, we show that the Hodge dual between the Maurer Caftan equation and the equation of motion gives the hidden symmetry in the moduli space of Green-Schwarz superstring. Thus by twisty transforming the vielbeins, we can express the currents of the paper [I. Bena, J. Polchinski, and R. Roiban, Phys. Rev. D 69 （2004） 0460021 as the Lax connections bv a uniaue spectral narameter.

关键词： Green-Schwarz superstring Hodge duallity hidden symmetry

hidden Sequence Repeats: Additional Evidence for the Origin of TIM-Barrel Family

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Journal of Biomedical Science and Engineering 2016年第6期9卷 307-314页

作者： Xiaofeng Ji Yuan Zheng Zhipeng Wang Jun Sheng Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao China

Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from duplication. As one of the six popular folds (super-folds) possessing an approximate structural symmetry, the triosephosphate isomerase barrel (TIM-barrel) domain has been widely studied. Using modified recurrent quantification analysis of primary sequences, we identified the same 2-, 3-, and 4-fold symmetry pattern as their tertiary structures. This result indicates that the symmetry in tertiary structure is coded by symmetry in the primary sequence and that the TIM-barrel adopts a 2-, 3-, or 4-fold repeat pattern during evolution. This discovery will be useful for understanding the evolutionary mechanisms of this protein family and the symmetry pattern that may be a clue into the ancient origin of duplication of half-barrels or the β a unit.

关键词： TIM-Barrel hidden symmetry Primary Sequences Repeat Pattern Recurrence Quantification Analysis