The Experts below are selected from a list of 67791 Experts worldwide ranked by ideXlab platform
Jianhua Jiang - One of the best experts on this subject based on the ideXlab platform.
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accidental degeneracy in photonic bands and Topological Phase transitions in two dimensional core shell dielectric photonic crystals
Optics Express, 2016Co-Authors: Haixiao Wang, Huanyang Chen, Jianhua JiangAbstract:A simple core-shell two-dimensional photonic crystal is studied where the triangular lattice symmetry and the C6 point group symmetry give rich physics in accidental touching points of photonic bands. We systematically evaluate different types of accidental nodal points at the Brillouin zone center for transverse-magnetic harmonic modes when the geometry and permittivity of the core-shell material are continuously tuned. The accidental nodal points can have different dispersions and Topological properties (i.e., Berry Phases). These accidental nodal points can be the critical states lying between a Topological Phase and a normal Phase of the photonic crystal. They are thus very important for the study of Topological photonic states. We show that, without breaking time-reversal symmetry, by tuning the geometry of the core-shell material, a Phase transition into the photonic quantum spin Hall insulator can be achieved. Here the “spin” is defined as the orbital angular momentum of a photon. We study the Topological Phase transition as well as the properties of the edge and bulk states and their application potentials in optics.
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accidental degeneracy and Topological Phase transitions in two dimensional core shell dielectric photonic crystals
arXiv: Materials Science, 2016Co-Authors: Haixiao Wang, Huanyang Chen, Jianhua JiangAbstract:A simple core-shell two-dimensional photonic crystal is studied where the triangle lattice symmetry and $C_{6v}$ rotation symmetry leads to rich physics in the study of accidental degeneracy's in photonic bands. We systematically evaluate different types of accidental nodal points, depending on the dispersions around them and their Topological properties, when the geometry and permittivity are continuously changed. These accidental nodal points can be the critical states lying between a Topological Phase and a normal Phase and are thus important for the study of Topological photonic states. In time-reversal systems, this leads to the photonic quantum spin Hall insulator where the spin is defined upon the orbital angular momentum for transverse-magnetic polarization. We study the Topological Phase transition as well as the properties of the edge and bulk states and their application potentials in optics.
Haixiao Wang - One of the best experts on this subject based on the ideXlab platform.
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accidental degeneracy in photonic bands and Topological Phase transitions in two dimensional core shell dielectric photonic crystals
Optics Express, 2016Co-Authors: Haixiao Wang, Huanyang Chen, Jianhua JiangAbstract:A simple core-shell two-dimensional photonic crystal is studied where the triangular lattice symmetry and the C6 point group symmetry give rich physics in accidental touching points of photonic bands. We systematically evaluate different types of accidental nodal points at the Brillouin zone center for transverse-magnetic harmonic modes when the geometry and permittivity of the core-shell material are continuously tuned. The accidental nodal points can have different dispersions and Topological properties (i.e., Berry Phases). These accidental nodal points can be the critical states lying between a Topological Phase and a normal Phase of the photonic crystal. They are thus very important for the study of Topological photonic states. We show that, without breaking time-reversal symmetry, by tuning the geometry of the core-shell material, a Phase transition into the photonic quantum spin Hall insulator can be achieved. Here the “spin” is defined as the orbital angular momentum of a photon. We study the Topological Phase transition as well as the properties of the edge and bulk states and their application potentials in optics.
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accidental degeneracy and Topological Phase transitions in two dimensional core shell dielectric photonic crystals
arXiv: Materials Science, 2016Co-Authors: Haixiao Wang, Huanyang Chen, Jianhua JiangAbstract:A simple core-shell two-dimensional photonic crystal is studied where the triangle lattice symmetry and $C_{6v}$ rotation symmetry leads to rich physics in the study of accidental degeneracy's in photonic bands. We systematically evaluate different types of accidental nodal points, depending on the dispersions around them and their Topological properties, when the geometry and permittivity are continuously changed. These accidental nodal points can be the critical states lying between a Topological Phase and a normal Phase and are thus important for the study of Topological photonic states. In time-reversal systems, this leads to the photonic quantum spin Hall insulator where the spin is defined upon the orbital angular momentum for transverse-magnetic polarization. We study the Topological Phase transition as well as the properties of the edge and bulk states and their application potentials in optics.
Erez Berg - One of the best experts on this subject based on the ideXlab platform.
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No-go theorem for a time-reversal invariant Topological Phase in noninteracting systems coupled to conventional superconductors
Physical Review B, 2016Co-Authors: Arbel Haim, Erez Berg, Karsten Flensberg, Yuval OregAbstract:We prove that a system of noninteracting electrons proximity coupled to a conventional $s$-wave superconductor cannot realize a time-reversal invariant Topological Phase. This is done by showing that for such a system, in either one or two dimensions, the Topological invariant of the corresponding symmetry class (DIII) is always trivial. Our results suggest that the pursuit of Majorana bound states in time-reversal invariant systems should be aimed at interacting systems or at proximity to unconventional superconductors.
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gapless symmetry protected Topological Phase of fermions in one dimension
Physical Review B, 2015Co-Authors: Anna Keselman, Erez BergAbstract:We consider a one-dimensional, time-reversal-invariant system with attractive interactions and spin-orbit coupling. Such a system is gapless due to the strong quantum fluctuations of the superconducting order parameter. However, we show that a sharply defined Topological Phase with protected, exponentially localized edge states exists. If one of the spin components is conserved, the protection of the edge modes can be understood as a consequence of the presence of a spin gap. In the more general case, the localization of the edge states arises from a gap to single particle excitations in the bulk. We consider specific microscopic models and demonstrate both analytically and numerically (using density matrix renormalization group calculations) that they can support the Topologically non-trivial Phase.
Huanyang Chen - One of the best experts on this subject based on the ideXlab platform.
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accidental degeneracy in photonic bands and Topological Phase transitions in two dimensional core shell dielectric photonic crystals
Optics Express, 2016Co-Authors: Haixiao Wang, Huanyang Chen, Jianhua JiangAbstract:A simple core-shell two-dimensional photonic crystal is studied where the triangular lattice symmetry and the C6 point group symmetry give rich physics in accidental touching points of photonic bands. We systematically evaluate different types of accidental nodal points at the Brillouin zone center for transverse-magnetic harmonic modes when the geometry and permittivity of the core-shell material are continuously tuned. The accidental nodal points can have different dispersions and Topological properties (i.e., Berry Phases). These accidental nodal points can be the critical states lying between a Topological Phase and a normal Phase of the photonic crystal. They are thus very important for the study of Topological photonic states. We show that, without breaking time-reversal symmetry, by tuning the geometry of the core-shell material, a Phase transition into the photonic quantum spin Hall insulator can be achieved. Here the “spin” is defined as the orbital angular momentum of a photon. We study the Topological Phase transition as well as the properties of the edge and bulk states and their application potentials in optics.
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accidental degeneracy and Topological Phase transitions in two dimensional core shell dielectric photonic crystals
arXiv: Materials Science, 2016Co-Authors: Haixiao Wang, Huanyang Chen, Jianhua JiangAbstract:A simple core-shell two-dimensional photonic crystal is studied where the triangle lattice symmetry and $C_{6v}$ rotation symmetry leads to rich physics in the study of accidental degeneracy's in photonic bands. We systematically evaluate different types of accidental nodal points, depending on the dispersions around them and their Topological properties, when the geometry and permittivity are continuously changed. These accidental nodal points can be the critical states lying between a Topological Phase and a normal Phase and are thus important for the study of Topological photonic states. In time-reversal systems, this leads to the photonic quantum spin Hall insulator where the spin is defined upon the orbital angular momentum for transverse-magnetic polarization. We study the Topological Phase transition as well as the properties of the edge and bulk states and their application potentials in optics.
Morais C Smith - One of the best experts on this subject based on the ideXlab platform.
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staircase to higher order Topological Phase transitions
Physical Review Letters, 2018Co-Authors: P Cats, A Quelle, Oscar Viyuela, M A Martindelgado, Morais C SmithAbstract:We find a series of Topological Phase transitions of increasing order, beyond the more standard second-order Phase transition in a one-dimensional Topological superconductor. The jumps in the order of the transitions depend on the range of the pairing interaction, which is parametrized by an algebraic decay with exponent α. Remarkably, in the limit α = 1 the order of the Topological transition becomes infinite. We compute the critical exponents for the series of higher-order transitions in exact form and find that they fulfill the hyperscaling relation. We also study the critical behavior at the boundary of the system and discuss potential experimental platforms of magnetic atoms in superconductors.
