scholarly journals Atomic-scale fatigue mechanism of ferroelectric tunnel junctions

2021 ◽  
Vol 7 (48) ◽  
Author(s):  
Yihao Yang ◽  
Ming Wu ◽  
Xingwen Zheng ◽  
Chunyan Zheng ◽  
Jibo Xu ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Atomic Scale ◽  
Fatigue Mechanism

Atomic-Scale Structure and Local Chemistry of CoFeB–MgO Magnetic Tunnel Junctions

Nano Letters ◽  
2016 ◽  
Vol 16 (3) ◽  
pp. 1530-1536 ◽  
Author(s):  
Zhongchang Wang ◽  
Mitsuhiro Saito ◽  
Keith P. McKenna ◽  
Shunsuke Fukami ◽  
Hideo Sato ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Scale Structure ◽  
Atomic Scale ◽  
Atomic Scale Structure

scholarly journals A comprehensive picture in the view of atomic scale on piezoelectricity of ZnO tunnel junctions: The first principles simulation

AIP Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 065217 ◽  
Author(s):  
Genghong Zhang ◽  
Weijin Chen ◽  
Jia Zhu ◽  
Gelei Jiang ◽  
Qiang Sheng ◽  
...  
Keyword(s):  
First Principles ◽  
Tunnel Junctions ◽  
Atomic Scale ◽  
Comprehensive Picture

First Principles Study of Atomic-Scale Al2O3 Films as Insulators for Magnetic Tunnel Junctions

2000 ◽  
Vol 39 (Part 2, No. 5B) ◽  
pp. L479-L481 ◽  
Author(s):  
Noriko Watari ◽  
Mineo Saito ◽  
Hisanao Tsuge ◽  
Osamu Sugino ◽  
Shuhei Ohnishi
Keyword(s):  
First Principles ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Atomic Scale ◽  
First Principles Study ◽  
Al2o3 Films

scholarly journals Atomic scale piezoelectricity and giant piezoelectric resistance effect in gallium nitride tunnel junctions under compressive strain

2016 ◽  
Vol 65 (10) ◽  
pp. 107701
Author(s):  
Zhang Geng-Hong ◽  
Zhu Jia ◽  
Jiang Ge-Lei ◽  
Wang Biao ◽  
Zheng Yue
Keyword(s):  
Gallium Nitride ◽  
Tunnel Junctions ◽  
Compressive Strain ◽  
Atomic Scale

Atomic-scale spectroscopic imaging of CoFeB/Mg–B–O/CoFeB magnetic tunnel junctions

2009 ◽  
Vol 95 (3) ◽  
pp. 032506 ◽  
Author(s):  
J. J. Cha ◽  
J. C. Read ◽  
W. F. Egelhoff ◽  
P. Y. Huang ◽  
H. W. Tseng ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Spectroscopic Imaging ◽  
Atomic Scale

scholarly journals Electric field spectroscopy of material defects in transmon qubits

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Jürgen Lisenfeld ◽  
Alexander Bilmes ◽  
Anthony Megrant ◽  
Rami Barends ◽  
Julian Kelly ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Electric Fields ◽  
Defect Formation ◽  
Tunnel Junctions ◽  
Dipole Moments ◽  
Device Fabrication ◽  
Superconducting Qubits ◽  
Atomic Scale ◽  
Large Area ◽  
Tunnel Barriers

AbstractSuperconducting integrated circuits have demonstrated a tremendous potential to realize integrated quantum computing processors. However, the downside of the solid-state approach is that superconducting qubits suffer strongly from energy dissipation and environmental fluctuations caused by atomic-scale defects in device materials. Further progress towards upscaled quantum processors will require improvements in device fabrication techniques, which need to be guided by novel analysis methods to understand and prevent mechanisms of defect formation. Here, we present a technique to analyse individual defects in superconducting qubits by tuning them with applied electric fields. This provides a spectroscopy method to extract the defects’ energy distribution, electric dipole moments, and coherence times. Moreover, it enables one to distinguish defects residing in Josephson junction tunnel barriers from those at circuit interfaces. We find that defects at circuit interfaces are responsible for about 60% of the dielectric loss in the investigated transmon qubit sample. About 40% of all detected defects are contained in the tunnel barriers of the large-area parasitic Josephson junctions that occur collaterally in shadow evaporation, and only $$\approx$$≈3% are identified as strongly coupled defects, which presumably reside in the small-area qubit tunnel junctions. The demonstrated technique provides a valuable tool to assess the decoherence sources related to circuit interfaces and to tunnel junctions that is readily applicable to standard qubit samples.

Structure and migration of planar defects in crystals observed in atomic scale

1978 ◽  
Vol 36 (1) ◽  
pp. 284-285 ◽  
Author(s):  
H. Hashimoto ◽  
Y. Sugimoto ◽  
Y. Takai ◽  
H. Endoh
Keyword(s):  
Electron Microscope ◽  
Rotation Angle ◽  
Crystal Surface ◽  
Electron Gun ◽  
Atomic Scale ◽  
Present Observation ◽  
Twist Boundary ◽  
Optical Magnification ◽  
Zinc Crystal ◽  
And Migration

As was demonstrated by the present authors that atomic structure of simple crystal can be photographed by the conventional 100 kV electron microscope adjusted at “aberration free focus (AFF)” condition. In order to operate the microscope at AFF condition effectively, highly stabilized electron beams with small energy spread and small beam divergence are necessary. In the present observation, a 120 kV electron microscope with LaB6 electron gun was used. The most of the images were taken with the direct electron optical magnification of 1.3 million times and then magnified photographically.1. Twist boundary of ZnSFig. 1 is the image of wurtzite single crystal with twist boundary grown on the surface of zinc crystal by the reaction of sulphur vapour of 1540 Torr at 500°C. Crystal surface is parallel to (00.1) plane and electron beam is incident along the axis normal to the crystal surface. In the twist boundary there is a dislocation net work between two perfect crystals with a certain rotation angle.

Resolution in the scanning tunneling microscope

1991 ◽  
Vol 49 ◽  
pp. 488-489
Author(s):  
R. J. Wilson ◽  
D. D. Chambliss ◽  
S. Chiang ◽  
V. M. Hallmark
Keyword(s):  
Scanning Tunneling Microscope ◽  
Fundamental Principle ◽  
Atomic Scale ◽  
Lateral Resolution ◽  
Scanning Tunneling ◽  
Electronic Noise ◽  
Vertical Resolution ◽  
Tunneling Microscopy ◽  
Spatial Profile ◽  
Theoretical Analyses

Scanning tunneling microscopy (STM) has been used for many atomic scale observations of metal and semiconductor surfaces. The fundamental principle of the microscope involves the tunneling of evanescent electrons through a 10Å gap between a sharp tip and a reasonably conductive sample at energies in the eV range. Lateral and vertical resolution are used to define the minimum detectable width and height of observed features. Theoretical analyses first discussed lateral resolution in idealized cases, and recent work includes more general considerations. In all cases it is concluded that lateral resolution in STM depends upon the spatial profile of electronic states of both the sample and tip at energies near the Fermi level. Vertical resolution is typically limited by mechanical and electronic noise.

What catalysis needs from the electron microscopist

1988 ◽  
Vol 46 ◽  
pp. 694-695
Author(s):  
Alexis T. Bell
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Catalyst Deactivation ◽  
Surface Composition ◽  
Internal Surface ◽  
Active Phase ◽  
Atomic Scale ◽  
Metal Catalyst ◽  
Internal Surface Area ◽  
Porous Support

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.

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