The van der Waals diameter of a silicon atom is 220 pm,more than three orders of magnitude smaller than the wavelength of visible light.It is a common belief that events on a picometer scale cannot significantly influ...The van der Waals diameter of a silicon atom is 220 pm,more than three orders of magnitude smaller than the wavelength of visible light.It is a common belief that events on a picometer scale cannot significantly influence light with wavelengths thousands of times larger.However,rather than using conventional light,the recent works demonstrated that topologically structured light offers the possibility of metrology at subatomic scale.展开更多
Floquet engineering provides a versatile platform for realizing and manipulating diverse exotic topological phases inaccessible in equilibrium.Under the irradiation of circularly or elliptically polarized light,the si...Floquet engineering provides a versatile platform for realizing and manipulating diverse exotic topological phases inaccessible in equilibrium.Under the irradiation of circularly or elliptically polarized light,the sizable spin-orbit couplings in group-IV Xene materials(e.g.,silicene,germanene,stanene)lead to topological phase transitions(TPT)from quantum spin Hall(QSH)to quantum anomalous Hall(QAH)states,governed by spin-degeneracy broken with band closing and reopening process in one of the spin components.Fascinatingly,a large gapped(≥35 meV)QAH effect with a Chern number C=±2 can be introduced under a wide range of laser parameters,lifting limitations of conventional atomic building blocks to achieve long-range magnetism and enabling Chern-insulating behaviors above room temperature.A complex phase diagram for such TPTs is predicted.This work addresses transitions between two-dimensional QSH and QAH states via Floquet engineering,which will stimulate experimental realization of above-room-temperature QAH in group-IV Xenes.展开更多
文摘The van der Waals diameter of a silicon atom is 220 pm,more than three orders of magnitude smaller than the wavelength of visible light.It is a common belief that events on a picometer scale cannot significantly influence light with wavelengths thousands of times larger.However,rather than using conventional light,the recent works demonstrated that topologically structured light offers the possibility of metrology at subatomic scale.
基金supported by National Natural Science Foundation of China(No.12025407 and No.12450401)National Key Research and Development Program of China(No.2021YFA1400201)Chinese Academy of Sciences(No.YSBR-047 and No.XDB33030100).
文摘Floquet engineering provides a versatile platform for realizing and manipulating diverse exotic topological phases inaccessible in equilibrium.Under the irradiation of circularly or elliptically polarized light,the sizable spin-orbit couplings in group-IV Xene materials(e.g.,silicene,germanene,stanene)lead to topological phase transitions(TPT)from quantum spin Hall(QSH)to quantum anomalous Hall(QAH)states,governed by spin-degeneracy broken with band closing and reopening process in one of the spin components.Fascinatingly,a large gapped(≥35 meV)QAH effect with a Chern number C=±2 can be introduced under a wide range of laser parameters,lifting limitations of conventional atomic building blocks to achieve long-range magnetism and enabling Chern-insulating behaviors above room temperature.A complex phase diagram for such TPTs is predicted.This work addresses transitions between two-dimensional QSH and QAH states via Floquet engineering,which will stimulate experimental realization of above-room-temperature QAH in group-IV Xenes.
