3,290 research outputs found
Floquet Majorana fermions in driven hexagonal lattice systems
We propose Floquet chiral topological superconducting systems hosting Floquet
Majorana fermions, which consist of hexagonal lattices in proximity to
superconductors with shining circularly polarized light. Specially for bilayer
graphene system, we demonstrate that there exist three topological phases
determined by certain parameters, namely, the amplitude and frequency of the
induced light. The number of chiral Floquet Majorana edge states is confirmed
by calculating Chern number analytically and energy spectrum in ribbon
geometry. Moreover, this proposal is generalized to other hexagonal lattice
systems, such as monolayer graphene and silicene. Notably, the parameter range
of induced light to achieve the chiral Floquet Majorana edge states is
experimentally feasible, and the corresponding Floquet Majorana fermions can be
probed based on differential conductance using scanning tunneling spectroscopy.Comment: 9 pages, 8 figure
Study on the optimization system of supporting schemes for foundation pit
At present, there are various supporting schemes for foundation pit that could be adopted in actual projects; however, there are also certain differences in construction cost and applicability of different schemes. To guarantee reasonable and efficient choice of supporting schemes for foundation pit, it is necessary to implement selection of supporting schemes purposefully. This essay discusses mainly the optimization system of supporting schemes for foundation pit. Through analysis of the affecting factors of supporting schemes of foundation pit, comprehensive optimization system of supporting schemes for foundation pit has been constructed, optimization model of supporting schemes based on TOPSIS has been created and comprehensive optimization system of supporting schemes for foundation pit has also been established
Realization of the Single-pair-Weyl Phonons with the Maximum Charge Number in Acoustic Crystals
To observe the Weyl phonon (WP) with the maximum charge and to design a
realistic material structure containing only single-pair-WPs have long been
considered two challenges in the field of topology physics. Here we have
successfully designed an acoustic crystal to realize the single-pair-WPs with
the maximum charge for the first time. Our theoretical simulations on acoustic
band dispersions demonstrate that protected by the time-reversal symmetry
() and the point group symmetries, a WP with the charge -4
() and another WP with are located at the
high-symmetry point and R, respectively, with the absence of any other
kinds of WPs. Moreover, the singe-pair-WPs obtained here are designed by the
simplest two-band mode, and the related quadruple-helicoid Fermi acrs can be
observed clearly in experiments, since they aren't covered by any bulk bands
and hybridized by other kinds of WPs. Our theoretical results provide a
reliable acoustic crystal to study the topological properties of the
single-pair-WPs with the maximum charge for experimentalists in this field.Comment: 7 pages; 4 figure
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