scholarly journals Ultrahigh-resolution scanning microwave impedance microscopy of moiré lattices and superstructures

2020 ◽  
Vol 6 (50) ◽  
pp. eabd1919
Author(s):  
Kyunghoon Lee ◽  
M. Iqbal Bakti Utama ◽  
Salman Kahn ◽  
Appalakondaiah Samudrala ◽  
Nicolas Leconte ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
High Resolution Imaging ◽  
Two Dimensional ◽  
Direct Visualization ◽  
Ambient Conditions ◽  
Ultrahigh Resolution ◽  
Inhomogeneous Strain ◽  
Structural Details ◽  
Resolution Imaging ◽  
Better Than

Two-dimensional heterostructures composed of layers with slightly different lattice vectors exhibit new periodic structure known as moiré lattices, which, in turn, can support novel correlated and topological phenomena. Moreover, moiré superstructures can emerge from multiple misaligned moiré lattices or inhomogeneous strain distributions, offering additional degrees of freedom in tailoring electronic structure. High-resolution imaging of the moiré lattices and superstructures is critical for understanding the emerging physics. Here, we report the imaging of moiré lattices and superstructures in graphene-based samples under ambient conditions using an ultrahigh-resolution implementation of scanning microwave impedance microscopy. Although the probe tip has a gross radius of ~100 nm, spatial resolution better than 5 nm is achieved, which allows direct visualization of the structural details in moiré lattices and the composite super-moiré. We also demonstrate artificial synthesis of novel superstructures, including the Kagome moiré arising from the interplay between different layers.

scholarly journals High Resolution Imaging Forty Years Ago

1994 ◽  
Vol 158 ◽  
pp. 337-341
Author(s):  
R. C. Jennison
Keyword(s):  
High Resolution ◽  
Point Sources ◽  
Resolving Power ◽  
High Angular Resolution ◽  
Electromagnetic Spectrum ◽  
High Resolution Imaging ◽  
Resolution Imaging ◽  
Optical Telescopes ◽  
Very High ◽  
Better Than

This conference is concerned with the very high resolution imaging of cosmic sources in many parts of the electromagnetic spectrum. Various techniques are now available and the equipment is often automated and highly sophisticated but the term ‘very high angular resolution’ is comparative. Many of the problems existed over forty years ago when the best resolving power was about half a degree and the two major radio ‘stars’ appeared to be point sources. Very high resolution imaging in those days was the struggle to reach one minute of arc and Hanbury Brown had set his sights on considerably better than one second of arc with the concept of the intensity interferometer. The dream was to achieve a resolving power comparable to that of optical telescopes.

Moiré patterns in electron microscopy with atomic focuser crystals

1999 ◽  
Vol 55 (3) ◽  
pp. 533-542 ◽  
Author(s):  
J. M. Cowley ◽  
Newton Ooi ◽  
R. E. Dunin-Borkowski
Keyword(s):  
Electron Microscopy ◽  
High Resolution Imaging ◽  
Crystal Lattices ◽  
Individual Crystal ◽  
Moire Patterns ◽  
Resolution Imaging ◽  
The Individual ◽  
Thin Crystal ◽  
Moiré Patterns ◽  
Better Than

The periodic array of very fine cross-overs formed at the exit face of a thin `atomic focuser' crystal, illuminated by a parallel electron beam, may be used to form moiré patterns with a specimen crystal such that the structure of the specimen crystal may be derived with a resolution of better than 0.5 Å. Computer simulations of the moiré pattern formation have been made for the simple idealized case of two parallel gold-like lattices having a 10% difference in lattice constant. Moiré images are shown for the case of a small objective aperture in the viewing electron microscope such that the individual crystal lattices are not resolved and for a larger objective aperture for which the individual crystal lattices are resolved and the intensity is measured at the positions of the atoms of the atomic focuser crystal. The latter case confirms the viability of the scheme for ultra-high-resolution imaging of general specimens by use of a thin-crystal periodic atomic focuser, as previously proposed.

Off-Axis STEM or TEM Holography Combined with Four-Dimensional Diffraction Imaging

2004 ◽  
Vol 10 (1) ◽  
pp. 9-15 ◽  
Author(s):  
J.M. Cowley
Keyword(s):  
Reference Beam ◽  
Transmission Function ◽  
Two Dimensional ◽  
Data Set ◽  
Ultrahigh Resolution ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Diffraction Imaging ◽  
Resolution Imaging ◽  
Dimensional Section

Ultrahigh-resolution imaging may be achieved using modifications of the off-axis holography scheme in a scanning transmission electron microscopy (STEM) instrument equipped with one or more electrostatic biprisms in the illuminating system. The resolution is governed by the diameter of a reference beam, reduced by channeling through a line of atoms in an atomic-focuser crystal. Alternatively, the off-axis holography may be combined with the Rodenburg method in which a four-dimensional data set is obtained by recording a nanodiffraction pattern from each point of the specimen as the incident beams are scanned. An ultrahigh-resolution image is derived by computer processing to give a particular two-dimensional section of this data set. The large amount of data recording and data processing involved with this method may be avoided if the two-dimensional section is derived by recording the hologram while the four beams produced by two perpendicular biprisms are scanned in opposing directions across the specimen by varying the voltages on the biprisms. An equivalent scheme for conventional TEM is also possible. In each case, the complex transmission function of the specimen may be derived and resolutions of about 0.05 nm may be expected.

scholarly journals Direct visualization of cell division using high-resolution imaging of M-phase of the cell cycle

2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Michael Hesse ◽  
Alexandra Raulf ◽  
Gregor-Alexander Pilz ◽  
Christian Haberlandt ◽  
Alexandra M. Klein ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
High Resolution ◽  
High Resolution Imaging ◽  
Direct Visualization ◽  
M Phase ◽  
Resolution Imaging

Fabrication of CdZnTe Strip Detectors for Large Area Arrays

1997 ◽  
Vol 487 ◽  
Author(s):  
C. M. Stahle ◽  
Z. Q. Shi ◽  
K. Hu ◽  
S. D. Barthelmy ◽  
S. J. Snodgrass ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Resolution Imaging ◽  
Two Dimensional ◽  
Large Area ◽  
Array Design ◽  
Nuclear Medical Imaging ◽  
Strip Detectors ◽  
Resolution Imaging ◽  
Strip Detector ◽  
Imaging And Spectroscopy

AbstractA CdZnTe strip detector large area array (∼ 60 cm2 with 36 detectors) with capabilities for high resolution imaging and spectroscopy has been built as a prototype for a space flight gamma ray burst instrument. The detector array also has applications in nuclear medical imaging. Two dimensional orthogonal strip detectors with 100 μm pitch have been fabricated and tested. Details for the array design, fabrication and evaluation of the detectors will be presented.

Fabrication of Cdznte Strip Detectors for Large Area Arrays

1997 ◽  
Vol 484 ◽  
Author(s):  
C. M. Stahle ◽  
Z. Q. Shi ◽  
K. Hu ◽  
S. D. Barthelmy ◽  
S. J. Snodgrass ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Resolution Imaging ◽  
Two Dimensional ◽  
Large Area ◽  
Array Design ◽  
Nuclear Medical Imaging ◽  
Strip Detectors ◽  
Resolution Imaging ◽  
Strip Detector ◽  
Imaging And Spectroscopy

AbstractA CdZnTe strip detector large area array (∼ 60 cm2 with 36 detectors) with capabilities for high resolution imaging and spectroscopy has been built as a prototype for a space flight gamma ray burst instrument. The detector array also has applications in nuclear medical imaging. Two dimensional orthogonal strip detectors with 100 gm pitch have been fabricated and tested. Details for the array design, fabrication and evaluation of the detectors will be presented.

scholarly journals High-resolution imaging of a cell-attached nanointerface using a gold-nanoparticle two-dimensional sheet

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Shihomi Masuda ◽  
Yuhki Yanase ◽  
Eiji Usukura ◽  
Sou Ryuzaki ◽  
Pangpang Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Gold Nanoparticle ◽  
High Resolution Imaging ◽  
Two Dimensional ◽  
A Cell ◽  
Resolution Imaging
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