Magnetic topological semimetals have been at the forefront of condensed matter physics due to their ability to exhibit exotic transport phenomena.Investigating the interplay between magnetic and topological orders in ...Magnetic topological semimetals have been at the forefront of condensed matter physics due to their ability to exhibit exotic transport phenomena.Investigating the interplay between magnetic and topological orders in systems with broken time-reversal symmetry is crucial for realizing non-trivial quantum effects.We delve into the electronic structure of the rare-earth-based antiferromagnetic Dirac semimetal EuMg_(2)Bi_(2) using first-principles calculations and angle-resolved photoemission spectroscopy.Our calculations reveal that the spin-orbit coupling(SOC)in EuMg_(2)Bi_(2) prompts an insulator to topological semimetal transition,with the Dirac bands protected by crystal symmetries.The linearly dispersive states near the Fermi level,primarily originating from Bi 6p orbitals,are observed on both the(001)and(100)surfaces,confirming that EuMg_(2)Bi_(2) is a three-dimensional topological Dirac semimetal.This research offers pivotal insights into the interplay between magnetism,SOC and topological phase transitions in spintronics applications.展开更多
We propose a new method for the development of multi-beam systems for the spatial alignment and stability of beams based on the error separation technique.This method avoids alignment errors caused by coupling effect ...We propose a new method for the development of multi-beam systems for the spatial alignment and stability of beams based on the error separation technique.This method avoids alignment errors caused by coupling effect of piezoelectric devices,inaccurate correction calculations,and detection mode of the angular deviation.According to the results by external detectors,the error value of spatial alignment and the root mean square[RMS]of deviations under control during 1 h can be equivalent to approximately 0.87 and 1.06 nm at the sample plane under an oil immersion lens[focal length f=2 mm].The RMS of deviations is less than one-third of those currently reported for multi-beam systems;therefore,higher alignment and stability accuracy can be achieved with our proposed method.展开更多
Optical singularity is pivotal in nature and has attracted wide interest from many disciplines nowadays,including optical communication,quantum optics,and biomedical imaging.Visualizing vortex lines formed by phase si...Optical singularity is pivotal in nature and has attracted wide interest from many disciplines nowadays,including optical communication,quantum optics,and biomedical imaging.Visualizing vortex lines formed by phase singularities and fabricating chiral nanostructures using the evolution of vortex lines are of great significance.In this paper,we introduce a promising method based on two-photon polymerization direct laser writing(2PP-DLW)to record the morphology of vortex lines generated by tightly focused multi-vortex beams(MVBs)at the nanoscale.Due to Gouy phase,the singularities of the MVBs rotate around the optical axis and move towards each other when approaching the focal plane.The propagation dynamics of vortex lines are recorded by 2PP-DLW,which explicitly exhibits the evolution of the phase singularities.Additionally,the MVBs are employed to fabricate stable three-dimensional chiral nanostructures due to the spiral-forward property of the vortex line.Because of the obvious chiral features of the manufactured nanostructures,a strong vortical dichroism is observed when excited by the light carrying orbital angular momentum.A number of applications can be envisioned with these chiral nanostructures,such as optical sensing,chiral separation,and information storage.展开更多
Optical microscopy is an essential tool for exploring the structures and activities of cells and tissues.To break the limit of resolution caused by diffraction,researchers have made continuous advances and innovations...Optical microscopy is an essential tool for exploring the structures and activities of cells and tissues.To break the limit of resolution caused by diffraction,researchers have made continuous advances and innovations to improve the resolution of optical microscopy since the 1990s.These contributions,however,still make sub-10nm imaging an obstacle.Here,we name a series of technologies as modulated illumination localization microscopy(MILM),which makes ultra-high-resolution imaging practical.Besides,we review the recent progress since 2017 when MINFLUX was proposed and became the inspiration and foundation for the follow-up devel-opment of MILM.This review divides MILM into two types:point-scanning and wide-field.The schematics,principles and future research directions of MILM are discussed elaborately.展开更多
In this paper,we propose a new fluorescence emission difference microscopy(FED)technique based on polarization modulation.An electro-optical modulator(EOM)is used to switch the excitation beam between the horizontal a...In this paper,we propose a new fluorescence emission difference microscopy(FED)technique based on polarization modulation.An electro-optical modulator(EOM)is used to switch the excitation beam between the horizontal and vertical polarization states at a high frequency,which leads to solid-and donut-shaped beams after spatial light modulation.Experiment on the fluorescent nanoparticles demonstrates that the proposed method can achieve~λ=4 spatial resolution.Using the proposed system,the dynamic imaging of subcellular structures in living cells over time is achieved.展开更多
In section 3.2,a reference(Ref.33)was missing in the first sentence.It was already listed in the References list and correctly cited in another portion of the text.Section 3.2,the second sentence incorrectly referred ...In section 3.2,a reference(Ref.33)was missing in the first sentence.It was already listed in the References list and correctly cited in another portion of the text.Section 3.2,the second sentence incorrectly referred to the"pattern in Fig.2";the pattern was specific to Fig.S6 in the Supplemental Material.展开更多
Direct laser writing(DLW)enables arbitrary three-dimensional nanofabrication.However,the diffraction limit poses a major obstacle for realizing nanometer-scale features.Furthermore,it is challenging to improve the fab...Direct laser writing(DLW)enables arbitrary three-dimensional nanofabrication.However,the diffraction limit poses a major obstacle for realizing nanometer-scale features.Furthermore,it is challenging to improve the fabrication efficiency using the currently prevalent single-focal-spot systems,which cannot perform high-throughput lithography.To overcome these challenges,a parallel peripheral-photoinhibition lithography system with a sub-40-nm two-dimensional feature size and a sub-20-nm suspended line width was developed in our study,based on two-photon polymerization DLW.The lithography efficiency of the developed system is twice that of conventional systems for both uniform and complex structures.The proposed system facilitates the realization of portable DLW with a higher resolution and throughput.展开更多
Stimulated emission depletion(STED)nanoscopy is one of the most well-developed nanoscopy techniques that can provide subdiffraction spatial resolution imaging.Here,we introduce dual-modulation difference STED microsco...Stimulated emission depletion(STED)nanoscopy is one of the most well-developed nanoscopy techniques that can provide subdiffraction spatial resolution imaging.Here,we introduce dual-modulation difference STED microscopy(dmdSTED)to suppress the background noise in traditional STED imaging.By applying respective time-domain modulations to the two continuous-wave lasers,signals are distributed discretely in the frequency spectrum and thus are obtained through lock-in demodulation of the corresponding frequencies.The background signals can be selectively eliminated from the effective signal without compromise of temporal resolution.We used nanoparticle,fixed cell,and perovskite coating experiments,as well as theoretical demonstration,to confirm the effectiveness of this method.We highlight dmdSTED as an idea and approach with simple implementation for improving the imaging quality,which substantially enlarges the versatility of STED nanoscopy.展开更多
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604302)the National Natural Science Foundation of China(Grant Nos.U1632266,11927807,and U2032207)the approval of the Proposal Assessing Committee of SiP.ME^(2) platform project(Proposal No.11227902)supported by the National Science Foundation of China。
文摘Magnetic topological semimetals have been at the forefront of condensed matter physics due to their ability to exhibit exotic transport phenomena.Investigating the interplay between magnetic and topological orders in systems with broken time-reversal symmetry is crucial for realizing non-trivial quantum effects.We delve into the electronic structure of the rare-earth-based antiferromagnetic Dirac semimetal EuMg_(2)Bi_(2) using first-principles calculations and angle-resolved photoemission spectroscopy.Our calculations reveal that the spin-orbit coupling(SOC)in EuMg_(2)Bi_(2) prompts an insulator to topological semimetal transition,with the Dirac bands protected by crystal symmetries.The linearly dispersive states near the Fermi level,primarily originating from Bi 6p orbitals,are observed on both the(001)and(100)surfaces,confirming that EuMg_(2)Bi_(2) is a three-dimensional topological Dirac semimetal.This research offers pivotal insights into the interplay between magnetism,SOC and topological phase transitions in spintronics applications.
基金supported by the National Key R&D Program of China(No.2021YFF0502700)National Natural Science Foundation of China(Nos.52105565 and 62105298)+3 种基金Natural Science Foundation of Zhejiang Province(Nos.LQ22F050015 and LQ22F050017)Major Program of Natural Science Foundation of Zhejiang Province(No.LD21F050002)Postdoctoral Research Foundation of China(No.2020M671822)Major Scientific Project of Zhejiang Lab(No.2020MC0AE01)。
文摘We propose a new method for the development of multi-beam systems for the spatial alignment and stability of beams based on the error separation technique.This method avoids alignment errors caused by coupling effect of piezoelectric devices,inaccurate correction calculations,and detection mode of the angular deviation.According to the results by external detectors,the error value of spatial alignment and the root mean square[RMS]of deviations under control during 1 h can be equivalent to approximately 0.87 and 1.06 nm at the sample plane under an oil immersion lens[focal length f=2 mm].The RMS of deviations is less than one-third of those currently reported for multi-beam systems;therefore,higher alignment and stability accuracy can be achieved with our proposed method.
基金National Key Research and Development Program of China(2021YFF0502700)China Postdoctoral Science Foundation(2022M722905)+2 种基金Zhejiang Provincial Ten Thousand Plan for Young Top Talents(2020R52001)Major Program of Natural Science Foundation of Zhejiang Province(LD21F050002)"Pioneer"and"Leading Goose"Research and Development Program of Zhejiang Province(2023C01051,2023C01186)。
文摘Optical singularity is pivotal in nature and has attracted wide interest from many disciplines nowadays,including optical communication,quantum optics,and biomedical imaging.Visualizing vortex lines formed by phase singularities and fabricating chiral nanostructures using the evolution of vortex lines are of great significance.In this paper,we introduce a promising method based on two-photon polymerization direct laser writing(2PP-DLW)to record the morphology of vortex lines generated by tightly focused multi-vortex beams(MVBs)at the nanoscale.Due to Gouy phase,the singularities of the MVBs rotate around the optical axis and move towards each other when approaching the focal plane.The propagation dynamics of vortex lines are recorded by 2PP-DLW,which explicitly exhibits the evolution of the phase singularities.Additionally,the MVBs are employed to fabricate stable three-dimensional chiral nanostructures due to the spiral-forward property of the vortex line.Because of the obvious chiral features of the manufactured nanostructures,a strong vortical dichroism is observed when excited by the light carrying orbital angular momentum.A number of applications can be envisioned with these chiral nanostructures,such as optical sensing,chiral separation,and information storage.
基金This work was financially sponsored by National Natural Science Foundation of China(61735017,61827825)Major Program of the Natural Science Foundation of Zhejiang Province(LD21F050002)+1 种基金Key Research and Development Program of Zhejiang Province(2020C01116)Fundamental Research Funds for the Central Universities(K20200132),Zhejiang Lab(2020MC0AE01)and Zhejiang Provincial Ten Thousand Plan for Young Top Talents(2020R52001).Y.S.and L.Y.contributed equally to this work.
文摘Optical microscopy is an essential tool for exploring the structures and activities of cells and tissues.To break the limit of resolution caused by diffraction,researchers have made continuous advances and innovations to improve the resolution of optical microscopy since the 1990s.These contributions,however,still make sub-10nm imaging an obstacle.Here,we name a series of technologies as modulated illumination localization microscopy(MILM),which makes ultra-high-resolution imaging practical.Besides,we review the recent progress since 2017 when MINFLUX was proposed and became the inspiration and foundation for the follow-up devel-opment of MILM.This review divides MILM into two types:point-scanning and wide-field.The schematics,principles and future research directions of MILM are discussed elaborately.
基金supported in part by the National Natural Science Foundation of China(61827825,62125504,and 61735017)Major Program of the Natural Science Foundation of Zhejiang Province(LD21F050002)+2 种基金Key Research and Development Program of Zhejiang Province(2020C01116)Zhejiang Lab(2020MC0AE01)China Postdoctoral Science Foundation(BX2021272).
文摘In this paper,we propose a new fluorescence emission difference microscopy(FED)technique based on polarization modulation.An electro-optical modulator(EOM)is used to switch the excitation beam between the horizontal and vertical polarization states at a high frequency,which leads to solid-and donut-shaped beams after spatial light modulation.Experiment on the fluorescent nanoparticles demonstrates that the proposed method can achieve~λ=4 spatial resolution.Using the proposed system,the dynamic imaging of subcellular structures in living cells over time is achieved.
文摘In section 3.2,a reference(Ref.33)was missing in the first sentence.It was already listed in the References list and correctly cited in another portion of the text.Section 3.2,the second sentence incorrectly referred to the"pattern in Fig.2";the pattern was specific to Fig.S6 in the Supplemental Material.
基金the National Key Research and Development Program of China(Grant No.2021YFF0502700)the National Natural Science Foundation of China(Grant Nos.62105298,52105565,and 22105180)+2 种基金China Postdoctoral Science Foundation(Grant Nos.2020M671823 and 2020M681956)the Natural Science Foundation of Zhejiang Province,China(Grant Nos.LD21F050002,LQ22F050017,and LQ22F050015)the Major Scientific Project of Zhejiang Lab,China(Grant No.2020MC0AE01).
文摘Direct laser writing(DLW)enables arbitrary three-dimensional nanofabrication.However,the diffraction limit poses a major obstacle for realizing nanometer-scale features.Furthermore,it is challenging to improve the fabrication efficiency using the currently prevalent single-focal-spot systems,which cannot perform high-throughput lithography.To overcome these challenges,a parallel peripheral-photoinhibition lithography system with a sub-40-nm two-dimensional feature size and a sub-20-nm suspended line width was developed in our study,based on two-photon polymerization DLW.The lithography efficiency of the developed system is twice that of conventional systems for both uniform and complex structures.The proposed system facilitates the realization of portable DLW with a higher resolution and throughput.
基金financially sponsored by the National Natural Science Foundation of China(62125504,61827825,6173501731901059)+5 种基金Major Program of the Natural Science Foundation of Zhejiang Province(LD21F050002)Key Research and Development Program of Zhejiang Province(2020C01116)Fundamental Research Funds for the Central Universities(K20200132)Zhejiang Lab(2020MC0AE01)Zhejiang Provincial Ten Thousand Plan for Young Top Talents(2020R52001)China Postdoctoral Science Foundation(2021TQ0275)。
文摘Stimulated emission depletion(STED)nanoscopy is one of the most well-developed nanoscopy techniques that can provide subdiffraction spatial resolution imaging.Here,we introduce dual-modulation difference STED microscopy(dmdSTED)to suppress the background noise in traditional STED imaging.By applying respective time-domain modulations to the two continuous-wave lasers,signals are distributed discretely in the frequency spectrum and thus are obtained through lock-in demodulation of the corresponding frequencies.The background signals can be selectively eliminated from the effective signal without compromise of temporal resolution.We used nanoparticle,fixed cell,and perovskite coating experiments,as well as theoretical demonstration,to confirm the effectiveness of this method.We highlight dmdSTED as an idea and approach with simple implementation for improving the imaging quality,which substantially enlarges the versatility of STED nanoscopy.