连续谱束缚态(Bound States in the Continuum, BICs)因其高品质因数(Q值)的特性而受到广泛关注,其中对称保护BICs是目前研究最为深入的一种,利用天然双曲型超材料(α-MoO_(3))设计了连续谱束缚态(BICs)的超表面(MS),通过改变结构中缺...连续谱束缚态(Bound States in the Continuum, BICs)因其高品质因数(Q值)的特性而受到广泛关注,其中对称保护BICs是目前研究最为深入的一种,利用天然双曲型超材料(α-MoO_(3))设计了连续谱束缚态(BICs)的超表面(MS),通过改变结构中缺口的大小将对称保护的BICs转变为准BICs,发现在频率f=19.68 THz时,Q值达到最高值772.1.对反射光谱和多极理论深入分析发现这一现象是由不同多极矩综合作用形成的.展开更多
传统THz器件长期受限于衍射极限导致的辐射损耗,其品质因子(Q因子)普遍低于10~5,严重制约了通信与传感性能。针对这一技术瓶颈,本研究基于拓扑光子学理论,设计了一种具有C6v对称性的硅基超表面,在THz频段实现了拓扑保护的高Q因子谐振。...传统THz器件长期受限于衍射极限导致的辐射损耗,其品质因子(Q因子)普遍低于10~5,严重制约了通信与传感性能。针对这一技术瓶颈,本研究基于拓扑光子学理论,设计了一种具有C6v对称性的硅基超表面,在THz频段实现了拓扑保护的高Q因子谐振。通过构建三角形晶格光子晶体平板,在晶胞内引入圆柱型蚀刻孔实现对称性保护,并采用理想磁导体边界条件分离TE模式,将连续域束缚态(bound states in the continuum,BIC)的拓扑保护机制引入THz频段。结果显示,Γ点处Q因子达到1010量级,且BIC位于远场辐射的偏振涡旋中心,验证了BIC机制及其拓扑特性,仿真结果良好。最终实现的Q因子较传统器件提升了多个数量级,且拓扑保护机制可以显著抑制加工缺陷与环境扰动对谐振性能的影响,为低损耗通信器件、光学可编程技术与量子光源设计提供了新范式。展开更多
A theory based on the superposition principle is developed to uncover the basic physics of wave behavior in a finite grating of N unit cells.The theory reveals that bound states in the continuum(BICs)of infinite quali...A theory based on the superposition principle is developed to uncover the basic physics of wave behavior in a finite grating of N unit cells.The theory reveals that bound states in the continuum(BICs)of infinite quality factor(Q-factor)can be supported by such a grating when perfect reflection is introduced at its boundaries.If geometrical perturbations are introduced into the structure,the dark BICs transform into bright quasi-BICs with finite Q-factor,maintaining spectral characteristics nearly identical to those of quasi-BICs supported by infinite gratings.When the boundaries are replaced with high-reflectivity metallic mirrors,the Q-factor of the resonant mode is reduced to be finite;however,it can be much larger than that in the corresponding nanostructure with open boundaries and can be tuned over a large range by varying the number of unit cells or boundary conditions.展开更多
The unique wave-manipulation capabilities of zero-index metamaterials(ZIMs)offer a new opportunity for realizing bound states in the continuum(BICs).However,the relationship between anomalous scattering and BICs remai...The unique wave-manipulation capabilities of zero-index metamaterials(ZIMs)offer a new opportunity for realizing bound states in the continuum(BICs).However,the relationship between anomalous scattering and BICs remains underexplored when parity–time(PT)symmetry is introduced.In this work,we demonstrate that a BIC splits into a pair of lasing modes carrying opposite topological charges by introducing PT symmetry through gain-loss cylinders embedded in ZIM layers.Theoretical analysis and numerical simulations reveal that lasing and unidirectional transparency phenomena result from the singularities and exceptional points of the scattering matrix.Moreover,exceptional points can be tuned via propagation phase modulation in the air gap,and their coalescence produces quasi-BICs with symmetric responses.This work provides a framework for manipulating BICs and topological lasing modes in non-Hermitian systems,offering new insights for designing non-Hermitian photonic devices.展开更多
We report the bifurcation of bound states in the continuum(BICs) in a dissipative cavity magnonic system, where a BIC splits into a pair of BICs. We theoretically analyze BICs in a dissipative cavity magnonic system a...We report the bifurcation of bound states in the continuum(BICs) in a dissipative cavity magnonic system, where a BIC splits into a pair of BICs. We theoretically analyze BICs in a dissipative cavity magnonic system and derive the critical condition for BICs bifurcation. Based on the theoretical results, we experimentally tune the dissipative photon–magnon coupling strength and demonstrate precise control over the detuning and number of BICs. When the dissipative coupling strength reaches a critical value, we observe the bifurcation of BICs, which is consistent with the theoretical prediction. Our systematic investigation of the evolution of BICs concerning the dissipative coupling strength and the discovery of the BIC bifurcation may enhance the sensitivity of BICs to external perturbations, potentially enabling applications in ultrasensitive detection.展开更多
In China,approximately 13% of people living with human immunodeficiency virus(HIV)(PLWH)are receiving lopinavir/ritonavir(LPV/r)-based regimens.These PLWH typically have a history of either treatment failure or intole...In China,approximately 13% of people living with human immunodeficiency virus(HIV)(PLWH)are receiving lopinavir/ritonavir(LPV/r)-based regimens.These PLWH typically have a history of either treatment failure or intolerance to first-line efavirenz-based regimens.Given the considerable pill burden and adverse effects associated with LPV/r,treatment optimization is important for this population.This multicenter retrospective study aimed to evaluate the efficacy and safety of switching from LPV/r-based regimens to the single-tablet regimen of bictegravir/emtricitabine/tenofovir alafenamide(BIC/FTC/TAF).Virological suppression rates(HIV-RNA<40 copies/mL)were primarily compared between the 48-week periods before and after switching to BIC/FTC/TAF.CD4 counts and metabolic data were also assessed.A total of 461 PLWH were recruited between January 2021 and December 2023,with 92.2% being male,a median age of 38 years,and a median antiretroviral therapy duration of 8 years.Prior to initiating LPV/r,23.0%(106/461)had documented virological failure.During LPV/r treatment,18.9%(20/106)of these individuals experienced viral rebound.Among all participants,the overall virological suppression rates significantly increased from 94.6%(pre-switch)to 98.6%(post-switch)(P<0.001).Notably,among participants with prior virological failure,suppression rates improved significantly from 81.1%to 97.2%(P<0.001),whereas no significant difference was observed in those without such history(from 98.6% to 99.2%,P=0.764).The median triglyceride level decreased from 2.4 mmol/L to 1.8 mmol/L(P<0.001),while no difference in CD4 counts was observed.These findings demonstrate that BIC/FTC/TAF is an effective and metabolically favorable treatment option for PLWH switching from LPV/r based regimens,regardless of whether they have a prior history of virological failure.展开更多
文摘连续谱束缚态(Bound States in the Continuum, BICs)因其高品质因数(Q值)的特性而受到广泛关注,其中对称保护BICs是目前研究最为深入的一种,利用天然双曲型超材料(α-MoO_(3))设计了连续谱束缚态(BICs)的超表面(MS),通过改变结构中缺口的大小将对称保护的BICs转变为准BICs,发现在频率f=19.68 THz时,Q值达到最高值772.1.对反射光谱和多极理论深入分析发现这一现象是由不同多极矩综合作用形成的.
文摘传统THz器件长期受限于衍射极限导致的辐射损耗,其品质因子(Q因子)普遍低于10~5,严重制约了通信与传感性能。针对这一技术瓶颈,本研究基于拓扑光子学理论,设计了一种具有C6v对称性的硅基超表面,在THz频段实现了拓扑保护的高Q因子谐振。通过构建三角形晶格光子晶体平板,在晶胞内引入圆柱型蚀刻孔实现对称性保护,并采用理想磁导体边界条件分离TE模式,将连续域束缚态(bound states in the continuum,BIC)的拓扑保护机制引入THz频段。结果显示,Γ点处Q因子达到1010量级,且BIC位于远场辐射的偏振涡旋中心,验证了BIC机制及其拓扑特性,仿真结果良好。最终实现的Q因子较传统器件提升了多个数量级,且拓扑保护机制可以显著抑制加工缺陷与环境扰动对谐振性能的影响,为低损耗通信器件、光学可编程技术与量子光源设计提供了新范式。
基金supported by the National Natural Science Foundation of China(Grant Nos.11874270 and 12174228)the Shenzhen Basic Research Special Project(Grant No.JCYJ20240813141606009)。
文摘A theory based on the superposition principle is developed to uncover the basic physics of wave behavior in a finite grating of N unit cells.The theory reveals that bound states in the continuum(BICs)of infinite quality factor(Q-factor)can be supported by such a grating when perfect reflection is introduced at its boundaries.If geometrical perturbations are introduced into the structure,the dark BICs transform into bright quasi-BICs with finite Q-factor,maintaining spectral characteristics nearly identical to those of quasi-BICs supported by infinite gratings.When the boundaries are replaced with high-reflectivity metallic mirrors,the Q-factor of the resonant mode is reduced to be finite;however,it can be much larger than that in the corresponding nanostructure with open boundaries and can be tuned over a large range by varying the number of unit cells or boundary conditions.
基金supported by the National Natural Science Foundation of China(Grant Nos.12504361,12274313,and 62465005)the Natural Science Foundation of Guangxi(Grant No.2025GXNSFBA069179)the Guangxi Colleges and Universities Young and Middle-aged Teachers’Basic Scientific Research Ability Enhancement Project(Grant No.2025KY0093)。
文摘The unique wave-manipulation capabilities of zero-index metamaterials(ZIMs)offer a new opportunity for realizing bound states in the continuum(BICs).However,the relationship between anomalous scattering and BICs remains underexplored when parity–time(PT)symmetry is introduced.In this work,we demonstrate that a BIC splits into a pair of lasing modes carrying opposite topological charges by introducing PT symmetry through gain-loss cylinders embedded in ZIM layers.Theoretical analysis and numerical simulations reveal that lasing and unidirectional transparency phenomena result from the singularities and exceptional points of the scattering matrix.Moreover,exceptional points can be tuned via propagation phase modulation in the air gap,and their coalescence produces quasi-BICs with symmetric responses.This work provides a framework for manipulating BICs and topological lasing modes in non-Hermitian systems,offering new insights for designing non-Hermitian photonic devices.
基金Project supported by the National Key Research and Development Program of China (Grant No. 2023YFA1406604)the National Natural Science Foundation of China (Grant Nos. 12274260, 12204306, 12122413, and 12474120)+1 种基金the Shandong Provincial Natural Science Foundation, China (Grant No. ZR2024YQ001)the Qilu Young Scholar Programs of Shandong University。
文摘We report the bifurcation of bound states in the continuum(BICs) in a dissipative cavity magnonic system, where a BIC splits into a pair of BICs. We theoretically analyze BICs in a dissipative cavity magnonic system and derive the critical condition for BICs bifurcation. Based on the theoretical results, we experimentally tune the dissipative photon–magnon coupling strength and demonstrate precise control over the detuning and number of BICs. When the dissipative coupling strength reaches a critical value, we observe the bifurcation of BICs, which is consistent with the theoretical prediction. Our systematic investigation of the evolution of BICs concerning the dissipative coupling strength and the discovery of the BIC bifurcation may enhance the sensitivity of BICs to external perturbations, potentially enabling applications in ultrasensitive detection.
基金supported by the Capital's Funds for Health Improvement and Research(CFH2024-2-2175).
文摘In China,approximately 13% of people living with human immunodeficiency virus(HIV)(PLWH)are receiving lopinavir/ritonavir(LPV/r)-based regimens.These PLWH typically have a history of either treatment failure or intolerance to first-line efavirenz-based regimens.Given the considerable pill burden and adverse effects associated with LPV/r,treatment optimization is important for this population.This multicenter retrospective study aimed to evaluate the efficacy and safety of switching from LPV/r-based regimens to the single-tablet regimen of bictegravir/emtricitabine/tenofovir alafenamide(BIC/FTC/TAF).Virological suppression rates(HIV-RNA<40 copies/mL)were primarily compared between the 48-week periods before and after switching to BIC/FTC/TAF.CD4 counts and metabolic data were also assessed.A total of 461 PLWH were recruited between January 2021 and December 2023,with 92.2% being male,a median age of 38 years,and a median antiretroviral therapy duration of 8 years.Prior to initiating LPV/r,23.0%(106/461)had documented virological failure.During LPV/r treatment,18.9%(20/106)of these individuals experienced viral rebound.Among all participants,the overall virological suppression rates significantly increased from 94.6%(pre-switch)to 98.6%(post-switch)(P<0.001).Notably,among participants with prior virological failure,suppression rates improved significantly from 81.1%to 97.2%(P<0.001),whereas no significant difference was observed in those without such history(from 98.6% to 99.2%,P=0.764).The median triglyceride level decreased from 2.4 mmol/L to 1.8 mmol/L(P<0.001),while no difference in CD4 counts was observed.These findings demonstrate that BIC/FTC/TAF is an effective and metabolically favorable treatment option for PLWH switching from LPV/r based regimens,regardless of whether they have a prior history of virological failure.
