20,661 research outputs found
Response analysis of an automobile shipping container
The design and development of automobile shipping containers to reduce enroute damage are discussed. Vibration tests were conducted to determine the system structural integrity. A dynamic analysis was made using NASTRAN and the results of the test and the analysis are compared
Geometric classification of non-Hermitian topological systems through the singularity ring
This work unveils how geometric features of two-band non-Hermitian
Hamiltonians can completely classify the topology of their eigenstates and
energy manifolds. Our approach generalizes the Bloch sphere visualization of
Hermitian systems to a ``Bloch torus'' picture for non-Hermitian systems, where
a singularity ring (SR) captures the degeneracy structure of generic
exceptional points. The SR picture affords convenient visualization of various
symmetry constraints and reduces their topological characterization to the
classification of simple intersection or winding behavior, as detailed by our
explicit study of chiral, sublattice, particle-hole and conjugated
particle-hole symmetries. In 1D, the winding number about the SR corresponds to
the band vorticity measurable through the Berry phase. In 2D, more complicated
winding behavior leads to a variety of phases that illustrate the richness of
the interplay between SR topology and geometry beyond mere Chern number
classification. Through a normalization procedure that puts generic 2-band
non-Hermitian Hamiltonians on equal footing, our SR approach also allows for
vivid visualization of the non-Hermitian skin effect.Comment: 17 pages, 15 figures, Comments are welcom
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