Research
Our current research topics include: method development of novel coherent high-resolution 3D imaging techniques - holography and coherent diffraction imaging; algorithms for wavefront propagation, simulation and reconstruction of holograms and diffraction patterns, iterative phase retrieval algorithms; convergent beam electron diffraction, 2D materials, coherent imaging with low-energy electrons (20 - 300 eV), wavefront modulation.
Team
Postdoc (joint with Adrian Wanner's group, PSI)
Former members
Postdoc (2022 - 2024)
semester project student (2023)
Master student (2021 - 2022)
Bachelor student (2022), joint with Dr Soichiro Tsujino
Open Positions
Students of the University of Zurich are welcome to contact us for Bachelor and Master projects. We currently have two PhD positions open. For postdoctoral positions, please contact us.
Teaching
Publications
2024
- A new family of septuple-layer 2D materials of MoSi2N4-like crystalsNature Reviews Physics (2024).
- Double-slit holography—a single-shot lensless imaging techniqueScientific Reports 14, 12528 (2024).
- Criteria for objects suitable for reconstruction from holograms and diffraction patternsJournal of the Optical Society of America A 41(11), 2219-2230 (2024).
2023
- Controlling topological states in bilayer grapheneNature Nanotechnology (2023).
- Fourier Transform Holography: A Lensless Imaging Technique, Its Principles and ApplicationsPhotonics 10(2), 153 (2023).
- Coherent imaging with low-energy electrons, quantitative analysisUltramicroscopy 253, 113807 (2023).
- Potentials of individual atoms by convergent beam electron diffractionCarbon 201, 244-250 (2023).
2022
- Low-dose shift- and rotation-invariant diffraction recognition imagingScientific Reports 12, 11202 (2022).
- Imaging defects in two-dimensional crystals by convergent-beam electron diffractionPhysical Review B 105, 184113 (2022).
2021
- Bragg holography of nano-crystalsUltramicroscopy 230, 113376 (2021).
- Three-dimensional structure from single two-dimensional diffraction intensity measurementPhysical Review Letters 127(6), 063601 (2021).
- Holographic convergent electron beam diffraction (CBED) imaging of two-dimensional crystalsSurface Review and Letters 28(8), 2140001 (2021).
- Phase retrieval methods applied to coherent imagingAdvances in Imaging and Electron Physics 218, 1 (2021).
- Symmetry of diffraction patterns of two-dimensional crystal structuresUltramicroscopy 228, 113336 (2021).
- Wavefront modulation and beam shaping into arbitrary three-dimensional intensity distributionsPhotonics 8(6), 179 (2021).
- Three-dimensional volumetric deconvolution in coherent optics and holographyApplied Optics 60(5), 1304 (2021).DOI: 10.1364/AO.412736
2020
- Holographic reconstruction of the interlayer distance of bilayer two-dimensional crystal samples from their convergent beam electron diffraction patternsUltramicroscopy 219, 113020 (2020).
- Holography and Coherent Diffraction Imaging with Low-(30–250 eV) and High-(80–300 keV) Energy Electrons: History, Principles, and Recent TrendsMaterials 13, 3089 (2020).DOI: 10.3390/ma13143089 "Congrats on your excellent review in Materials!" by John Spence
- Convergent beam electron diffraction of multilayer van der Waals structuresUltramicroscopy 212, 112976 (2020).
2019
- Iterative phase retrieval for digital holography (invited)Journal of the Optical Society of America 36, D31 (2019).
- Reconstruction of missing information in diffraction patterns and holograms by iterative phase retrievalOptics Communications 452, 56 (2019).
- Inelastic scattering and solvent scattering reduce dynamical diffraction in biological crystalsActa Crystallographica Section B 75, 52 (2019).
- Direct visualization of charge transport in suspended (or free-standing) DNA strands by low-energy electron microscopyScientific Reports 9, 8889 (2019).
- Lateral and axial resolution criteria in incoherent and coherent optics and holography, near- and far-field regimesApplied Optics 58, 3597 (2019).DOI: 10.1364/AO.58.003597
- Ultrafast holography enabled by quantum interference of ultrashort electronsScience Advances 5, eaav8358 (2019).
- Local photo-mechanical stiffness revealed in gold nanoparticles supracrystals by ultrafast small-angle electron diffractionStructural Dynamics 6, 024304 (2019).DOI: 10.1063/1.5091858
- Moiré structures in twisted bilayer graphene studied by transmission electron microscopyUltramicroscopy 197, 46 (2019).
- Stacking transition in rhombohedral graphiteFrontiers of Physics 14, 13608 (2019).
- Convergent and divergent beam electron holography and reconstruction of adsorbates on free-standing two-dimensional crystalsFrontiers of Physics 14, 13606 (2019).
2018
- Investigating Skyrmions Using Lorentz Transmission Electron MicroscopyMicroscopy and Microanalysis 24, 932 (2018).
- Three-dimensional double helical DNA structure directly revealed from its X-ray fiber diffraction pattern by iterative phase retrievalOptics Express 26, 30991 (2018).DOI: 10.1364/OE.26.030991
- Iterative phase retrieval in coherent diffractive imaging: practical issuesApplied Optics 57, 7187 (2018).DOI: 10.1364/AO.57.007187
- Algorithms and image formation in orbital tomographyPhysical Review B 98, 085426 (2018).
- Convergent beam electron holography for analysis of van der Waals heterostructuresPNAS 115, 7473 (2018).
- Metal adsorption and nucleation on free-standing graphene by low-energy electron point source microscopyNano Letters 18, 3421 (2018).
2017
- Resolution enhancement in in-line holography by numerical compensation of vibrationsOptics Express 25, 20109 (2017).DOI: 10.1364/OE.25.020109
- Imaging the potential distribution of charged adsorbates on graphene by low-energy electron holographyUltramicroscopy 182, 276 (2017).
- Three-dimensional surface topography of graphene by divergent beam electron diffractionNature Communications 8, 14440 (2017).DOI: 10.1038/ncomms14440
- Spatial coherence of electron beams from field emitters and its effect on the resolution of imaged objectsUltramicroscopy 175, 121 (2017).
- Imaging proteins at the single-molecule levelPNAS 114, 1474 (2017).
2016
- Application of iterative phase-retrieval algorithms to ARPES orbital tomographyNew Journal of Physics 18, 093041 (2016).
- Resolution enhancement by extrapolation of coherent diffraction images: a quantitative study about the limits and a numerical study of non-binary and phase objectsJournal of Microscopy 264, 2 (2016).DOI: 10.1111/jmi.12408
- Direct observation of individual charges and their dynamics on graphene by low-energy electron holographyNano Letters 16, 5469 (2016).
- Mapping unoccupied electronic states of freestanding graphene by angle-resolved low-energy electron transmissionPhysical Review B 94, 075424 (2016).
- Creating Airy beams employing a transmissive spatial light modulatorApplied Optics 55, 6095 (2016).DOI: 10.1364/AO.55.006095
- Inverted Gabor holography principle for tailoring arbitrary shaped three-dimensional beamsScientific Reports 6, 26312 (2016).DOI: 10.1038/srep26312
- Order/disorder dynamics in a dodecanethiol-capped gold nanoparticles supracrystal by small-angle ultrafast electron diffractionNano Letters 16, 2705 (2016).
- Invariant time-dependent exchange perturbation theory and its application to the particles collision problemHighlights in Theoretical Chemistry 11, 41 (2016).
2015
- Imaging outside the box: Resolution enhancement in X-ray coherent diffraction imaging by extrapolation of diffraction patternsApplied Physics Letters 107, 183102 (2015).DOI: 10.1063/1.4934879
- Filming the formation and fluctuation of skyrmion domains by cryo-Lorentz transmission electron microscopyPNAS112, 14212 (2015).
- The role of the coherence in the cross-correlation analysis of diffraction patterns from two-dimensional dense mono-disperse systemsScientific Report 5, 16573 (2015).DOI: 10.1038/srep16573
- Holography and coherent diffraction with low-energy electrons: A route towards structural biology at the single molecule levelUltramicroscopy 159, 395 (2015).
- Terahertz in-line digital holography of human hepatocellular carcinoma tissueScientific Reports 5, 8445 (2015).DOI: 10.1038/srep08445
- Low-energy electron holographic imaging of individual tobacco mosaic virionsApplied Physics Letters 107, 133101 (2015).DOI: 10.1063/1.4931607
- Invariant time-dependent exchange perturbation theory and its application to the particles collision problemTheoretical Chemistry Accounts 134, 1 (2015).
- Atomically resolved structural determination of graphene and its point defects via extrapolation assisted phase retrievalApplied Physics Letters 106, 021908 (2015).DOI: 10.1063/1.4906089
- Practical algorithms for simulation and reconstruction of digital in-line hologramsApplied Optics 54, 2424 (2015).DOI: 10.1364/AO.54.002424
- Reconstruction of purely absorbing, absorbing and phase-shifting, and strong phase-shifting objects from their single-shot in-line hologramsApplied Optics 54, 3932 (2015).DOI: 10.1364/AO.54.003925
2014
- Holographic time-resolved particle tracking by means of three-dimensional volumetric deconvolutionOptics Express 22, 20994 (2014).DOI: 10.1364/OE.22.020994
- On artefact-free reconstruction of low-energy (30-250 eV) electron hologramsUltramicroscopy 145, 22 (2014).
- Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolationOptics Express 22, 17236 (2014).DOI: 10.1364/OE.22.017236
- Low-energy electron holographic imaging of ultraclean graphene-supported gold-nanorodsUltramicroscopy 145, 80 (2014).
2013
- Pulsed electron holographyApplied Physics Letters 102, 203115 (2013).DOI: 10.1063/1.4807661
- Coherent diffraction and holographic imaging of individual biomolecules using low-energy electronsAdvancing Methods for Biomolecular Crystallography. NATO Science for Peace and Security Series A: Chemistry and Biology ~, 331 (2013).
- Resolution enhancement in digital holography by self-extrapolation of hologramsOptics Express 21, 7726 (2013).DOI: 10.1364/OE.21.007726
- Graphene unit cell imaging by holographic coherent diffractionPhysical Review Letters 110, 255501 (2013).
- Coherent microscopy at resolution beyond diffraction limit using post-experimental data extrapolationApplied Physics Letters 103, 204105 (2013).DOI: 10.1063/1.4831985
2012
- When holography meets coherent diffraction imagingOptics Express 20, 28871 (2012).DOI: 10.1364/OE.20.028871
- Non-destructive imaging of an individual proteinApplied Physics Letters 101, 093701 (2012).DOI: 10.1063/1.4748113
- Low-energy electron transmission imaging of clusters on free-standing grapheneApplied Physics Letters 101, 113117 (2012).DOI: 10.1063/1.4752717
2011
- Novel Fourier-domain constraint for fast phase retrieval in coherent diffraction imagingOptics Express 19, 19330 (2011).DOI: 10.1364/OE.19.019330
- Individual filamentous phage imaged by electron holographyEurropean Biophysics Journal 40, 1197 (2011).
2010
- Nondestructive imaging of individual biomoleculesPhysical Review Letters 104, 095501 (2010).
- Off-axis and inline electron holography: Experimental comparisonUltramicroscopy 110, 472 (2010).
- Depth-resolved holographic reconstructions by three-dimensional deconvolutionOptics Express 18, 22527 (2010).DOI: 10.1364/OE.18.022527
- Graphene as a transparent conductive support for studying biological molecules by transmission electron microscopyApplied Physics Letters 97, 153102 (2010).DOI: 10.1063/1.3492845
2009
- Simultaneous reconstruction of phase and amplitude contrast from a single holographic recordOptics Express 17, 10697 (2009).DOI: 10.1364/OE.17.010697
2007
- Solution to the twin image problem in holographyPhysical Review Letters 98, 233901 (2007).
2006
- Resorcin[4]arene cavitand-based molecular switchesAdvanced Functional Materials 16, 147 (2006).
- Direct evidence for conduction pathways in a solid electrolytePhysical Review Letters 97, 136601 (2006).
- A single-molecule study of polycrystalline microstructure by fluorescence polarization spectroscopyJournal of Luminescence 118, 111 (2006).
- A quantum mechanical scheme to reduce radiation damage in electron microscopyApplied Physics Letters 88, 164103 (2006).DOI: 10.1063/1.2191096
- Axisymmetric liquid hanging dropsJournal of Chemical Education 83, 117 (2006).DOI: 10.1021/ed083p117
2003
- Single molecule spectroscopyJournal of the Chinese Chemical Society 50, 477 (2003).
2002
- Theory of the Stark effect on single molecular spectroscopyJournal of the Chinese Chemical Society 49, 797 (2002).
- Higher-order Stark effect on single-moleculesChemical Physics 282, 109 (2002).
2000
- Radio-frequency Stark effect modulation of single-molecule linesJournal of Luminescence 86, 189 (2000).
1999
- Detection and spectroscopy of single molecules in rare gas matrices: dibenzanthanthrene in krypton and xenonChemical Physics Letters 311, 29 (1999).
- Imaging and spectroscopy of terrylene molecules isolated in vapor-deposited n-alkane matricesChemical Physics 247, 35 (1999).
- Absorption spectroscopy on single molecules in solidsJournal of Chemical Physics 111, 8755 (1999).DOI: 10.1063/1.480222
- Advanced holographic nondestructive testing system for residual stress analysisProceedings of SPIE 3678, 73 (1999).DOI: 10.1117/12.347399
1998
- Recording and reconstruction of reflection and transmission holograms with a cw laser diodeSPIE Proceedings 3293, 131 (1999).DOI: 10.1117/12.303646
- Pulse recording of slanted fringe holograms in DuPont photopolymerSPIE Proceedings 3294, 132 (1999).DOI: 10.1117/12.304533
- The method of exchange perturbation theory as applied to magnetic ordering in high-Tc materialsJournal of Experimental and Theoretical Physics 86, 2129 (1999).DOI: 10.1134/1.558587