scholarly journals Microwave Atom Chip Design

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 54
Author(s):  
William Miyahira ◽  
Andrew P. Rotunno ◽  
ShuangLi Du ◽  
Seth Aubin
Keyword(s):  
Transmission Lines ◽  
Relative Phase ◽  
Building Blocks ◽  
Atom Interferometry ◽  
Spin States ◽  
Atom Chip ◽  
Chip Design ◽  
Atom Chips ◽  
Atomic Transitions ◽  
Local Polarization

We present a toolbox of microstrip building blocks for microwave atom chips geared towards trapped atom interferometry. Transverse trapping potentials based on the AC Zeeman (ACZ) effect can be formed from the combined microwave magnetic near fields of a pair or a triplet of parallel microstrip transmission lines. Axial confinement can be provided by a microwave lattice (standing wave) along the microstrip traces. Microwave fields provide additional parameters for dynamically adjusting ACZ potentials: detuning of the applied frequency to select atomic transitions and local polarization controlled by the relative phase in multiple microwave currents. Multiple ACZ traps and potentials, operating at different frequencies, can be targeted to different spin states simultaneously, thus enabling spin-specific manipulation of atoms and spin-dependent trapped atom interferometry.

Optimizing atom interferometry on atom chips

2009 ◽  
Vol 57 (11-12) ◽  
pp. 1121-1132 ◽  
Author(s):  
U. Hohenester ◽  
J. Grond ◽  
J. Schmiedmayer
Keyword(s):  
Atom Interferometry ◽  
Atom Chips

ANALOG DENDRO-DENDRITIC ARRAYS WITH DIGITAL ON-CHIP LEARNING

1998 ◽  
Vol 08 (05n06) ◽  
pp. 571-587
Author(s):  
F. M. SALAM ◽  
Y. WANG ◽  
G. ERTEN
Keyword(s):  
Power Dissipation ◽  
Building Blocks ◽  
Cmos Technology ◽  
Digital Learning ◽  
Chip Design ◽  
Learning Capability ◽  
Chip Size ◽  
On Chip ◽  
Digital Circuitry ◽  
Fully Connected

A design of arrays of CMOS analog Dendro-dendritic Artificial Neural Network (DANN) chips with on-chip digital learning is described. The building blocks, namely, the neuron unit and the adaptive synapse, are employed to construct several architectures. One design comprises a reconfigurable fully-connected array chip integrating 50-neurons. A second array chip design integrates (9×9=81) neuron units and 825 locally-connected reconfigurable weights. In all cases, a connection is realized as a single (nonlinear) transistor with adaptive digital circuitry. The chip is designed and fabricated in 6.8 mm× 4.6 mm chip size using 2 μm CMOS technology. As an example of an application of the fabricated dendro-dendritic neural chips, real-time experiments are described in which the chips are used as a parallel digital coprocessor to demonstrate their applicability as pattern associators. These experiments entail learning an arbitrary binary image in about 10 ns with guaranteed learning capability. The stored image can subsequently be retrieved by images distorted by binary-noise in the order of 100 ns. The power dissipation of these chips in steady state is less than 5 mW using 0/5 V power supply.

A COMPARISON OF SILICON AND III–V TECHNOLOGY PERFORMANCE AND BUILDING BLOCK IMPLEMENTATIONS FOR 10 AND 40 Gb/s OPTICAL NETWORKING ICs

2003 ◽  
Vol 13 (01) ◽  
pp. 27-57 ◽  
Author(s):  
S. P. VOINIGESCU ◽  
D. S. McPHERSON ◽  
F. PERA ◽  
S. SZILAGYI ◽  
M. TAZLAUANU ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Transmission Lines ◽  
Leading Edge ◽  
Building Blocks ◽  
Optical Networking ◽  
Passive Components ◽  
Limiting Amplifier ◽  
Isolation Techniques ◽  
Sige Bicmos ◽  
Technology Comparison

Scalable models for both active and passive components are essential for the design of highly integrated fiber–optic physical layer ICs. This paper focuses on the various technology options available of 10 Gb/s and 40 Gb/s applications, on how their constituent components are modeled and what the characteristics and requirements are for the basic building blocks. As part of the technology comparison, an overview of the performance of leading edge Si CMOS, SiGe BiCMOS and III–V technologies is presented. Scalable models for SiGe HBTs and GaAs p–HEMTs are then compared with measured data for various device sizes. Inductors, varactors, transmission lines and isolation techniques on Si and III–V substrates are discussed next followed by technology–specific implementations of VCO and digital building blacks. Finally, Transimpedance Limiting Amplifier (TIALA) as well as laser and modulator driver designs in SiGe BiCMOS, InP HBT and GaAs p–HEMT processes using scalable device models are illustrated for 10 and 40 Gb/s fiber-optics applications.

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

Friedel'S law breakdown and interpretation of stacking fault images in tetrahedral semiconductors

1987 ◽  
Vol 45 ◽  
pp. 318-319
Author(s):  
Rob. W. Glaisher ◽  
A.E.C. Spargo
Keyword(s):  
Relative Phase ◽  
Point Group ◽  
Binary Compound ◽  
Stacking Fault ◽  
Fold Axis ◽  
Atom Pair ◽  
Tetrahedral Semiconductors ◽  
Group Symmetries ◽  
Thin Crystal ◽  
Phase Differences

Images of <11> oriented crystals with diamond structure (i.e. C,Si,Ge) are dominated by white spot contrast which, depending on thickness and defocus, can correspond to either atom-pair columns or tunnel sites. Olsen and Spence have demonstrated a method for identifying the correspondence which involves the assumed structure of a stacking fault and the preservation of point-group symmetries by correctly aligned and stigmated images. For an intrinsic stacking fault, a two-fold axis lies on a row of atoms (not tunnels) and the contrast (black/white) of the atoms is that of the {111} fringe containing the two-fold axis. The breakdown of Friedel's law renders this technique unsuitable for the related, but non-centrosymmetric binary compound sphalerite materials (e.g. GaAs, InP, CdTe). Under dynamical scattering conditions, Bijvoet related reflections (e.g. (111)/(111)) rapidly acquire relative phase differences deviating markedly from thin-crystal (kinematic) values, which alter the apparent location of the symmetry elements needed to identify the defect.

Cryo-TEM of amphiphilic polymer and amphiphile/polymer solutions

1993 ◽  
Vol 51 ◽  
pp. 876-877
Author(s):  
Yeshayahu Talmon
Keyword(s):  
Microstructural Characterization ◽  
Building Blocks ◽  
Quantitative Information ◽  
Physical Models ◽  
Specimen Preparation ◽  
Time Resolved ◽  
Temperature Changes ◽  
Temperature And Humidity ◽  
Microstructured Fluids ◽  
Air Streams

To achieve complete microstructural characterization of self-aggregating systems, one needs direct images in addition to quantitative information from non-imaging, e.g., scattering or Theological measurements, techniques. Cryo-TEM enables us to image fluid microstructures at better than one nanometer resolution, with minimal specimen preparation artifacts. Direct images are used to determine the “building blocks” of the fluid microstructure; these are used to build reliable physical models with which quantitative information from techniques such as small-angle x-ray or neutron scattering can be analyzed.To prepare vitrified specimens of microstructured fluids, we have developed the Controlled Environment Vitrification System (CEVS), that enables us to prepare samples under controlled temperature and humidity conditions, thus minimizing microstructural rearrangement due to volatile evaporation or temperature changes. The CEVS may be used to trigger on-the-grid processes to induce formation of new phases, or to study intermediate, transient structures during change of phase (“time-resolved cryo-TEM”). Recently we have developed a new CEVS, where temperature and humidity are controlled by continuous flow of a mixture of humidified and dry air streams.

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