scholarly journals Scalable, efficient ion-photon coupling with phase Fresnel lenses for large-scale quantum computing

2009 ◽  
Vol 9 (3&4) ◽  
pp. 203-214
Author(s):  
E.W. Streed ◽  
B.G. Norton ◽  
J.J. Chapman ◽  
D. Kielpinski
Keyword(s):  
Quantum Computing ◽  
Large Scale ◽  
Large Fraction ◽  
Numerical Aperture ◽  
Fresnel Lens ◽  
Ion Traps ◽  
Propagation Mode ◽  
Fresnel Lenses ◽  
Mode Tem ◽  
Photon Coupling

Efficient ion-photon coupling is an important component for large-scale ion-trap quantum computing. We propose that arrays of phase Fresnel lenses (PFLs) are a favorable optical coupling technology to match with multi-zone ion traps. Both are scalable technologies based on conventional micro-fabrication techniques. The large numerical apertures (NAs) possible with PFLs can reduce the readout time for ion qubits. PFLs also provide good coherent ion-photon coupling by matching a large fraction of an ion's emission pattern to a single optical propagation mode (TEM$_{00}$). To this end we have optically characterized a large numerical aperture phase Fresnel lens (NA=0.64) designed for use at 369.5 nm, the principal fluorescence detection transition for Yb$^+$ ions. A diffraction-limited spot $w_0=350\pm15$ nm ($1/e^2$ waist) with mode quality $M^2= 1.08\pm0.05$ was measured with this PFL. From this we estimate the minimum expected free space coherent ion-photon coupling to be 0.64\%, which is twice the best previous experimental measurement using a conventional multi-element lens. We also evaluate two techniques for improving the entanglement fidelity between the ion state and photon polarization with large numerical aperture lenses.

A Novel High Concentration Fresnel Lens as a Solar Concentrator

2021 ◽  
pp. 1-29
Author(s):  
Kuldeep Awasthi ◽  
Desireddy Shashidhar Reddy ◽  
Mohd. Kaleem Khan
Keyword(s):  
Optical Axis ◽  
Spherical Aberration ◽  
Spherical Surface ◽  
Fresnel Lens ◽  
High Concentration ◽  
Aperture Diameter ◽  
Convex Lens ◽  
Flat Base ◽  
Fresnel Lenses ◽  
Outer Vertex

Abstract This paper describes the design methodology for a novel Fresnel lens. The original Fresnel lens is obtained from a plano-convex lens, whose spherical surface is split into a number of divisions (called facets), collapsed onto the flat base. Thus, all the facets of the original Fresnel lens have the same radius as that of the plano-convex lens. The proposed design aims to achieve better ray concentration and reduced spherical aberration than the original Fresnel lens by constructing spherical facets with unequal radii. The centers and radii of facets are constrained so that the ray refracted from the bottom vertex of each facet on one side of the optical axis and the ray refracted from the outer vertex of the corresponding facet on the other side of the optical axis must intersect at the focal plane. The proposed lens design has resulted in a 275% gain in the concentration ratio and a 72.5% reduction in the spherical aberration compared to the original lens of the same aperture diameter and number of facets. The performance of both novel and original Fresnel lenses when used as solar concentrators with a conical coil receiver is evaluated. The novel Fresnel lens led to increased heat gain and resulted in a compact solar collector design.

scholarly journals Investigation of Atmospheric Rivers Impacting the Pigeon River Basin of the Southern Appalachian Mountains

2018 ◽  
Vol 33 (1) ◽  
pp. 283-299 ◽  
Author(s):  
Douglas K. Miller ◽  
David Hotz ◽  
Jessica Winton ◽  
Lukas Stewart
Keyword(s):  
North Carolina ◽  
River Basin ◽  
Large Scale ◽  
Large Fraction ◽  
Appalachian Mountains ◽  
Warm Season ◽  
Atmospheric Rivers ◽  
Southern Appalachian Mountains ◽  
Low Level ◽  
Southern Appalachian

Abstract Rainfall observations in the Pigeon River basin of the southern Appalachian Mountains over a 5-yr period (2009–14) are examined to investigate the synoptic patterns responsible for downstream flooding events as observed near Knoxville, Tennessee, and Asheville, North Carolina. The study is designed to address the hypothesis that atmospheric rivers (ARs) are primarily responsible for the highest accumulation periods observed by the gauge network and that these periods correspond to events having a societal hazard (flooding). The upper 2.5% (extreme) and middle 33% (normal) rainfall events flagged using the gauge network observations showed that half of the heaviest rainfall cases were associated with an AR. Of those extreme events having an AR influence, over 73% had a societal hazard defined as minor-to-major flooding at the USGS river gauge located in Newport, Tennessee, or flooding observations for locations near the Tennessee and North Carolina border reported in the Storm Data publication. Composites of extreme AR-influenced events revealed a synoptic pattern consisting of a highly amplified slow-moving positively tilted trough, suggestive of the anticyclonic Rossby wave breaking scenario that sometimes precedes hydrological events of high impact. Composites of extreme non-AR events indicated a large-scale weather pattern typical of a warm season scenario in which an anomalous low-level cyclone, cut off far from the primary upper-tropospheric jet, was located in the southeastern United States. AR events without a societal hazard represented a large fraction (75%–88%) of all ARs detected during the study period. Synoptic-scale weather patterns of these events were fast moving and had weak low-level atmospheric dynamics.

scholarly journals Quantum learning with noise and decoherence: a robust quantum neural network

2019 ◽  
Author(s):  
Elizabeth Behrman ◽  
Nam Nguyen ◽  
James Steck
Keyword(s):  
Neural Network ◽  
Quantum Computing ◽  
Large Scale ◽  
Learning Approaches ◽  
Quantum Neural Network ◽  
Quantum Learning ◽  
Learning With Noise ◽  
Robustness To Noise ◽  
Robust To Noise ◽  
Arbitrary Quantum

<p>Noise and decoherence are two major obstacles to the implementation of large-scale quantum computing. Because of the no-cloning theorem, which says we cannot make an exact copy of an arbitrary quantum state, simple redundancy will not work in a quantum context, and unwanted interactions with the environment can destroy coherence and thus the quantum nature of the computation. Because of the parallel and distributed nature of classical neural networks, they have long been successfully used to deal with incomplete or damaged data. In this work, we show that our model of a quantum neural network (QNN) is similarly robust to noise, and that, in addition, it is robust to decoherence. Moreover, robustness to noise and decoherence is not only maintained but improved as the size of the system is increased. Noise and decoherence may even be of advantage in training, as it helps correct for overfitting. We demonstrate the robustness using entanglement as a means for pattern storage in a qubit array. Our results provide evidence that machine learning approaches can obviate otherwise recalcitrant problems in quantum computing. </p> <p> </p>

scholarly journals Transcriptional and post-transcriptional regulation and transcriptional memory of chromatin regulators in response to low temperature

2019 ◽  
Author(s):  
K. Vyse ◽  
L. Faivre ◽  
M. Romich ◽  
M. Pagter ◽  
D. Schubert ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Low Temperature ◽  
Transcriptional Activation ◽  
Large Scale ◽  
Transcriptional Profiling ◽  
Large Fraction ◽  
Histone Variants ◽  
Transcriptional Level ◽  
Large Set ◽  
Dynamic Regulation

AbstractChromatin regulation ensures stable repression of stress-inducible genes under non-stress conditions and transcriptional activation and memory of such an activation of those genes when plants are exposed to stress. However, there is only limited knowledge on how chromatin genes are regulated at the transcriptional and post-transcriptional level upon stress exposure and relief from stress. We have therefore set-up a RT-qPCR-based platform for high-throughput transcriptional profiling of a large set of chromatin genes. We find that the expression of a large fraction of these genes is regulated by cold. In addition, we reveal an induction of several DNA and histone demethylase genes and certain histone variants after plants have been shifted back to ambient temperature (deacclimation), suggesting a role in the memory of cold acclimation. We also re-analyse large scale transcriptomic datasets for transcriptional regulation and alternative splicing (AS) of chromatin genes, uncovering an unexpected level of regulation of these genes, particularly at the splicing level. This includes several vernalization regulating genes whose AS results in cold-regulated protein diversity. Overall, we provide a profiling platform for the analysis of chromatin regulatory genes and integrative analyses of their regulation, suggesting a dynamic regulation of key chromatin genes in response to low temperature stress.

scholarly journals The effectiveness of a mini photovoltaic cell by using light LED bulbs as a source of photon energy

2021 ◽  
Vol 926 (1) ◽  
pp. 012090
Author(s):  
Mustofa ◽  
Iskandar ◽  
Muchsin ◽  
S Suluh ◽  
T M Kamaludin
Keyword(s):  
Energy Source ◽  
Output Power ◽  
Electrical Energy ◽  
Photovoltaic Cell ◽  
Fresnel Lens ◽  
Test Results ◽  
Light Spectrum ◽  
Pv Cell ◽  
Fresnel Lenses ◽  
Cell Module

Abstract Muxindo’s LED bulb is one of the brands that are widely used by Indonesian people as lighting in the home. This study aims to look at the effectiveness of the light spectrum of the 10, 15 and 20 Watt LED power bulbs as an energy source to generate electrical energy in monocrystalline mini photovoltaic (PV) cell module. The light spectrum is compared with and without the Fresnel lens before being transmitted to the PV surface. The test results show that the PV output power is much better with a Fresnel lens (4.06> 1.67) mW. The efficiency of PV with lens displays slightly different figures, 3.77% at 15 Watt bulb power, while without Fresnel lenses, PV efficiency is 4.86% with a 20 Watt bulb. Need further research, for example, with Philips brand LED bulbs

scholarly journals Large-scale microlens arrays on flexible substrate with improved numerical aperture for curved integral imaging 3D display

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wenwen Wang ◽  
Guixiong Chen ◽  
Yalian Weng ◽  
Xuyang Weng ◽  
Xiongtu Zhou ◽  
...  
Keyword(s):  
Large Scale ◽  
Flexible Substrate ◽  
Numerical Aperture ◽  
3D Display ◽  
Microlens Arrays ◽  
Integral Imaging
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