The Au/Al2O3/Al metal/insulator/metal junction(MIMJ) and Au/SiO2/Si metal/insulator/Si junction(MISJ) have been constructed successfully. The light emission of these junctions was mediated by surface plasmon-polariton...The Au/Al2O3/Al metal/insulator/metal junction(MIMJ) and Au/SiO2/Si metal/insulator/Si junction(MISJ) have been constructed successfully. The light emission of these junctions was mediated by surface plasmon-polaritons(SPPs) under surface roughness. The light emission from MISJ was more uniform and stable than that from MIMJ. The light power of MISJ was about 2~3 orders higher than that of MIMJ. The light emission spectrum of MISJ was analyzed especially. In the spectrum, there was one main peak located at the wavelength of 610 nm^640 nm, which was mainly due to the couple of SPP with the surface roughness at the Au/air and Au/SiO2 interfaces. A weak peak located at the shorter wavelength region in the spectrum was also found, which was caused by the direct radiation of doped-Si plasma oscillation.展开更多
Higher-order topological insulators(HOTIs),with topological corner or hinge states,have emerged as a thriving topic in the field of topological physics.However,few connections have been found for HOTIs with well-explo...Higher-order topological insulators(HOTIs),with topological corner or hinge states,have emerged as a thriving topic in the field of topological physics.However,few connections have been found for HOTIs with well-explored first-order topological insulators.Recently a proposal asserted that a significant bridge can be established between the HOTIs and Z2 topological insulators.When subjected to an inplane Zeeman field,corner states,the signature of the HOTIs,can be induced in a Z2 topological insulator.Such Zeeman fields can be produced,for example,by the ferromagnetic proximity effect or magnetic atom doping,which drastically increases the experimental complexity.Here,we show that a phononic crystal,designed as a bilayer of coupled acoustic cavities,exactly hosts the Kane-Mele model with built-in in-plane Zeeman fields.The helical edge states along the zigzag edges are gapped,and the corner states,localized spatially at the corners of the samples,appear in the gap.This verifies the Zeeman field induced higher-order topology.We further demonstrate the intriguing contrast properties of the corner states at the outer and inner corners in a hexagonal ring-shaped sample.展开更多
We investigate a tight-binding model of the ruby lattice with Rashba spin-orbit coupling. We calculate the band structure of the lattice and evaluate the Z2 topological indices. According to the Z2 topological indices...We investigate a tight-binding model of the ruby lattice with Rashba spin-orbit coupling. We calculate the band structure of the lattice and evaluate the Z2 topological indices. According to the Z2 topological indices and the band structure, we present the phase diagrams of the lattice with different filling fractions. We findthat topological insulators occur in some range of parameters at 1/6, 1/3, 1/2, 2/3 and 5/6 filling fractions. We analyze and discuss the characteristics of these topological insulators and their edge states.展开更多
基金National Natural Science Foundation of China(69576006)
文摘The Au/Al2O3/Al metal/insulator/metal junction(MIMJ) and Au/SiO2/Si metal/insulator/Si junction(MISJ) have been constructed successfully. The light emission of these junctions was mediated by surface plasmon-polaritons(SPPs) under surface roughness. The light emission from MISJ was more uniform and stable than that from MIMJ. The light power of MISJ was about 2~3 orders higher than that of MIMJ. The light emission spectrum of MISJ was analyzed especially. In the spectrum, there was one main peak located at the wavelength of 610 nm^640 nm, which was mainly due to the couple of SPP with the surface roughness at the Au/air and Au/SiO2 interfaces. A weak peak located at the shorter wavelength region in the spectrum was also found, which was caused by the direct radiation of doped-Si plasma oscillation.
基金supported by the National Natural Science Foundation of China(11890701,11974120,11974005,12074128,12074232,12125406,and 12174455)the National Key R&D Program of China(2018YFA0305800)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2019B151502012,2021B1515020086,and 2021A1515010347)the Science and Technology Projects in Guangzhou(202102020960)。
文摘Higher-order topological insulators(HOTIs),with topological corner or hinge states,have emerged as a thriving topic in the field of topological physics.However,few connections have been found for HOTIs with well-explored first-order topological insulators.Recently a proposal asserted that a significant bridge can be established between the HOTIs and Z2 topological insulators.When subjected to an inplane Zeeman field,corner states,the signature of the HOTIs,can be induced in a Z2 topological insulator.Such Zeeman fields can be produced,for example,by the ferromagnetic proximity effect or magnetic atom doping,which drastically increases the experimental complexity.Here,we show that a phononic crystal,designed as a bilayer of coupled acoustic cavities,exactly hosts the Kane-Mele model with built-in in-plane Zeeman fields.The helical edge states along the zigzag edges are gapped,and the corner states,localized spatially at the corners of the samples,appear in the gap.This verifies the Zeeman field induced higher-order topology.We further demonstrate the intriguing contrast properties of the corner states at the outer and inner corners in a hexagonal ring-shaped sample.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 11004028 and 11274061
文摘We investigate a tight-binding model of the ruby lattice with Rashba spin-orbit coupling. We calculate the band structure of the lattice and evaluate the Z2 topological indices. According to the Z2 topological indices and the band structure, we present the phase diagrams of the lattice with different filling fractions. We findthat topological insulators occur in some range of parameters at 1/6, 1/3, 1/2, 2/3 and 5/6 filling fractions. We analyze and discuss the characteristics of these topological insulators and their edge states.
