scholarly journals Topographic signatures and manipulations of Fe atoms, CO molecules and NaCl islands on superconducting Pb(111)

2022 ◽  
Vol 13 ◽  
pp. 1-9
Author(s):  
Carl Drechsel ◽  
Philipp D’Astolfo ◽  
Jung-Ching Liu ◽  
Thilo Glatzel ◽  
Rémy Pawlak ◽  
...  

Topological superconductivity emerging in one- or two-dimensional hybrid materials is predicted as a key ingredient for quantum computing. However, not only the design of complex heterostructures is primordial for future applications but also the characterization of their electronic and structural properties at the atomic scale using the most advanced scanning probe microscopy techniques with functionalized tips. We report on the topographic signatures observed by scanning tunneling microscopy (STM) of carbon monoxide (CO) molecules, iron (Fe) atoms and sodium chloride (NaCl) islands deposited on superconducting Pb(111). For the CO adsorption a comparison with the Pb(110) substrate is demonstrated. We show a general propensity of these adsorbates to diffuse at low temperature under gentle scanning conditions. Our findings provide new insights into high-resolution probe microscopy imaging with terminated tips, decoupling atoms and molecules by NaCl islands or tip-induced lateral manipulation of iron atoms on top of the prototypical Pb(111) superconducting surface.

2021 ◽  
Author(s):  
Carl Drechsel ◽  
Philipp D’Astolfo ◽  
Jung-Ching Liu ◽  
Thilo Glatzel ◽  
Rémy Pawlak ◽  
...  

Background: Topological superconductivity emerging in one- or two-dimensional hybrid materials is predicted as a key ingredient for quantum computing. However, not only the design of complex heterostructures is primordial for future applications but also the characterization of their electronic and structural properties at the atomic scale using the most advanced scanning probe microscopy techniques with functionalized tips.Results: We report on the topographic signatures observed by scanning tunneling microscopy (STM) of carbon monoxide (CO) molecules, iron (Fe) atoms and sodium chloride (NaCl) islands deposited on superconducting Pb(111). For the CO adsorption a comparison with the Pb(110) substrate is demonstrated. We show a general propensity of these adsorbates to diffuse at low temperature under gentle scanning conditions.Conclusion: Our findings provide new insights into high-resolution probe microscopy imaging with terminated tips, decoupling atoms and molecules by NaCl islands or tip-induced lateral manipulation of iron atoms on top of the prototypical Pb(111) superconducting surface.


1998 ◽  
Vol 4 (S2) ◽  
pp. 600-601
Author(s):  
John Rakovan ◽  
F. Hochella Michael

Since its invention inl982 scanning probe microscopy (SPM) has become an important analytical tool in every branch of physical science. The two most widely used types of SPM are atomic force Microscopy (AFM) and scanning tunneling microscopy (STM). Both AFM and STM allow measurement of the microtopography of a surface down to the atomic scale. Many spin-off applications such as lateral force and magnetic force allow measurement of a variety of the physical properties of a surface while imaging its microtopography. SPM can be done in both air and liquid and hence can be used to observe the interactions that take place at a solid-solution interface.SPM has been used in mineralogy and geochemistry since 1989. Here as in other applications the great strength of SPM is in the characterization of the heterogeneous nature of mineral surfaces and the ability to observe many geochemical processes in real time.


2007 ◽  
Vol 996 ◽  
Author(s):  
Kenta Arima ◽  
Hideyuki Hara ◽  
Yasuhisa Sano ◽  
Keita Yagi ◽  
Ryota Okamoto ◽  
...  

AbstractScanning tunneling microscopy (STM) observations are performed on 4H-SiC(0001) surfaces after wet-chemical preparation steps including HF treatments.1×1 structures are formed on a terrace together with other local structures. Their atomic images are investigated in conjunction with low-energy electron diffraction and electron spectroscopy for chemical analysis. It is suggested that each bright dot forming the 1×1 phase corresponds to an OH-terminated Si atom.


1994 ◽  
Vol 332 ◽  
Author(s):  
Naoki Yokoi ◽  
Hiroya Andoh ◽  
Mikio Takai

ABSTRACTThe geometric structure of GaAs (100) surfaces, treated in a (NH4)2Sx solution and annealed in N2 environment, has been studied in an atomic scale using high-resolution Rutherford backscattering (RBS), X-ray photoemission spectroscopy (XPS) and scanning tunneling microscopy (STM). RBS analysis using medium energy ion scattering (MEIS) could provide the thickness of the sulfur layer on the GaAs surface of about 1.5 monolayers. RBS channeling spectra indicated that the disorder of atoms in the surface region of S-terminated samples was smaller than that of untreated one. XPS spectra showed that S atoms on the surface bonded only As atoms. STM observation revealed that S atoms had a periodicity of 4 Å corresponding to that of Ga or As atoms in the (100) plane.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 85
Author(s):  
Raja S. R. Gajjela ◽  
Paul M. Koenraad

The fundamental understanding of quantum dot (QD) growth mechanism is essential to improve QD based optoelectronic devices. The size, shape, composition, and density of the QDs strongly influence the optoelectronic properties of the QDs. In this article, we present a detailed review on atomic-scale characterization of droplet epitaxy quantum dots by cross-sectional scanning tunneling microscopy (X-STM) and atom probe tomography (APT). We will discuss both strain-free GaAs/AlGaAs QDs and strained InAs/InP QDs grown by droplet epitaxy. The effects of various growth conditions on morphology and composition are presented. The efficiency of methods such as flushing technique is shown by comparing with conventional droplet epitaxy QDs to further gain control over QD height. A detailed characterization of etch pits in both QD systems is provided by X-STM and APT. This review presents an overview of detailed structural and compositional analysis that have assisted in improving the fabrication of QD based optoelectronic devices grown by droplet epitaxy.


MRS Bulletin ◽  
1993 ◽  
Vol 18 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Steven M. Hues ◽  
Richard J. Colton ◽  
Ernst Meyer ◽  
Hans-Joachim Güntherodt

Atomic force microscopy (AFM) was invented in 1986 by Binnig, Quate, and Gerber as “a new type of microscope capable of investigating surfaces of insulators on an atomic scale.” Stemming from developments in scanning tunneling microscopy (STM), it became possible to image insulators, organic and biological molecules, salts, glasses, and metal oxides — some under a variety of conditions, e.g., ambient pressure, in aqueous or cryogenic liquids, etc. In 1987, Mate and co-workers introduced a new application for AFM where atomic-scale frictional forces could be measured. Likewise, in 1989, Burnham and Colton used the AFM to measure the surface forces and nano-mechanical properties of materials. Today, there are many examples of using AFM as a high-resolution profilometer, surface force probe, and nanoindentor. Several new imaging techniques have been introduced; each depending on the type of force measured, e.g., magnetic, electrostatic, and capacitative. Because of the diverse nature of the field and instrumentation, the names “scanned probe microscopy” and “XFM” (where X stands for the force being measured, e.g., MFM is magnetic force microscopy) have been adopted.


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