scholarly journals Amplification of quadratic Hamiltonians

Quantum ◽  
2020 ◽  
Vol 4 ◽  
pp. 271 ◽  
Author(s):  
Christian Arenz ◽  
Denys I. Bondar ◽  
Daniel Burgarth ◽  
Cecilia Cormick ◽  
Herschel Rabitz
Keyword(s):  
Quantum System ◽  
Cavity Resonator ◽  
Environmental Noise ◽  
Continuous Variable ◽  
Detailed Knowledge ◽  
Dynamical Decoupling ◽  
Quadratic Hamiltonians ◽  
Full Knowledge ◽  
Potential Use

Speeding up the dynamics of a quantum system is of paramount importance for quantum technologies. However, in finite dimensions and without full knowledge of the details of the system, it is easily shown to be impossible. In contrast we show that continuous variable systems described by a certain class of quadratic Hamiltonians can be sped up without such detailed knowledge. We call the resultant procedure Hamiltonian amplification (HA). The HA method relies on the application of local squeezing operations allowing for amplifying even unknown or noisy couplings and frequencies by acting on individual modes. Furthermore, we show how to combine HA with dynamical decoupling to achieve amplified Hamiltonians that are free from environmental noise. Finally, we illustrate a significant reduction in gate times of cavity resonator qubits as one potential use of HA.

An atomic-resolution microscope study of Al contracts on GaAs

1986 ◽  
Vol 44 ◽  
pp. 726-727
Author(s):  
Z. Liliental-Weber ◽  
C. Nelson ◽  
R. Ludeke ◽  
R. Gronsky ◽  
J. Washburn
Keyword(s):  
High Speed ◽  
Schottky Contacts ◽  
Detailed Knowledge ◽  
The Past ◽  
Semiconductor Interfaces ◽  
Deposited Metal ◽  
Microwave Applications ◽  
Free Interfaces ◽  
Potential Use

The properties of metal/semiconductor interfaces have received considerable attention over the past few years, and the Al/GaAs system is of special interest because of its potential use in high-speed logic integrated optics, and microwave applications. For such materials a detailed knowledge of the geometric and electronic structure of the interface is fundamental to an understanding of the electrical properties of the contact. It is well known that the properties of Schottky contacts are established within a few atomic layers of the deposited metal. Therefore surface contamination can play a significant role. A method for fabricating contamination-free interfaces is absolutely necessary for reproducible properties, and molecularbeam epitaxy (MBE) offers such advantages for in-situ metal deposition under UHV conditions

scholarly journals Quantum dephasing induced by non-Markovian random telegraph noise

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xiangji Cai
Keyword(s):  
Master Equation ◽  
Quantum System ◽  
Conditional Probability ◽  
Quantum Information Processing ◽  
Open Quantum Systems ◽  
Modulation Frequency ◽  
Environmental Noise ◽  
Random Telegraph Noise ◽  
Telegraph Noise ◽  
Generalized Master Equation

AbstractWe theoretically study the dynamical dephasing of a quantum two level system interacting with an environment which exhibits non-Markovian random telegraph fluctuations. The time evolution of the conditional probability of the environmental noise is governed by a generalized master equation depending on the environmental memory effect. The expression of the dephasing factor is derived exactly which is closely associated with the memory kernel in the generalized master equation for the conditional probability of the environmental noise. In terms of three important types memory kernels, we discuss the quantum dephasing dynamics of the system and the non-Markovian character exhibiting in the dynamical dephasing induced by non-Markovian random telegraph noise. We show that the dynamical dephasing of the quantum system does not always exhibit non-Markovian character which results from that the non-Markovian character in the dephasing dynamics depends both on the environmental non-Markovian character and the interaction between the system and environment. In addition, the dynamical dephasing of the quantum system can be modulated by the external modulation frequency of the environment. This result is significant to quantum information processing and helpful for further understanding non-Markovian dynamics of open quantum systems.

scholarly journals Genetic analysis of a potato (Solanum tuberosum L.) breeding collection for southern Colombia using Single Nucleotide Polymorphism (SNP) markers

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248787
Author(s):  
Jhon A. Berdugo-Cely ◽  
Carolina Martínez-Moncayo ◽  
Tulio César Lagos-Burbano
Keyword(s):  
Linkage Disequilibrium ◽  
Genetic Analysis ◽  
Solanum Tuberosum L ◽  
Genetic Distances ◽  
Snp Markers ◽  
Detailed Knowledge ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Genetic Breeding ◽  
Potential Use

Detailed knowledge on genetic parameters such as diversity, structure, and linkage disequilibrium (LD) and identification of duplicates in a germplasm bank and/or breeding collection are essential to conservation and breeding strategies in any crop. Therefore, the potato genetic breeding collection at the Universidad de Nariño in Colombia, which is made up of diploid and tetraploid genotypes in two of the more diverse genebanks in the world, was analyzed with 8303 single nucleotide polymorphisms (SNP) from SolCAP version 1. In total, 144 genotypes from this collection were analyzed identifying an 57.2% of the polymorphic markers that allowed establishing two and three subpopulations that differentiated the diploid genotypes from the tetraploids. These subpopulations had high levels of heterozygosity and linkage disequilibrium. The diversity levels were higher in the tetraploid genotypes, while the LD levels were higher in the diploid genotypes. For the tetraploids, the genotypes from Peru had greater diversity and lower linkage disequilibrium than those from Colombia, which had slightly lower diversity and higher degrees of LD. The genetic analysis identified, adjusted and/or selected diploid and tetraploid genotypes under the following characteristics: 1) errors in classification associated with the level of ploidy; 2) presence of duplicates; and 3) genotypes with broad genetic distances and potential use in controlled hybridization processes. These analyses suggested that the potato genetic breeding collection at the Universidad de Nariño has a genetic base with a potential use in breeding programs for this crop in the Department of Nariño, in southern Colombia.

scholarly journals Phosphogypsum and its potential use in Croatia: challenges and opportunities

2021 ◽  
Vol 72 (3) ◽  
pp. 93-100
Author(s):  
Tomislav Bituh ◽  
Branko Petrinec ◽  
Božena Skoko ◽  
Dinko Babić ◽  
Davor Rašeta
Keyword(s):  
Sustainable Development ◽  
Phosphoric Acid ◽  
Human Health ◽  
Circular Economy ◽  
Hazardous Substances ◽  
Business Strategies ◽  
Detailed Knowledge ◽  
Challenges And Opportunities ◽  
Potential Use ◽  
Radiological Properties

Abstract Phosphogypsum (PG) is a waste by-product (residue) originating from the production of phosphoric acid and phosphate fertilisers. PG contains chemical and radioactive impurities, which is why it is mostly stockpiled in controlled areas. Worldwide, only about 15 % of PG is recycled or reused. Today, policies and business strategies prioritise sustainable development through circular economy, which certainly includes PG. This provides new opportunities for Croatia to manage its PG and make an effort to use it as an additive in different industries, such as agriculture and construction. Due to its chemical and radiological properties, PG can potentially cause problems for the environment and human health. Hence, before using PG, detailed knowledge of potential hazards is necessary to protect people and the environment. The aim of this review is to summarise available data on Croatian PG, compare them with other countries, and to identify knowledge gaps and the lack of data on potential hazardous substances in PG in order to assess the opportunities of using PG in Croatia.

scholarly journals Environmental noise spectroscopy with qubits subjected to dynamical decoupling

2017 ◽  
Vol 29 (33) ◽  
pp. 333001 ◽  
Author(s):  
P Szańkowski ◽  
G Ramon ◽  
J Krzywda ◽  
D Kwiatkowski ◽  
Ł Cywiński
Keyword(s):  
Environmental Noise ◽  
Dynamical Decoupling ◽  
Noise Spectroscopy

scholarly journals Dynamical decoupling and homogenization of continuous variable systems

2017 ◽  
Vol 50 (13) ◽  
pp. 135303 ◽  
Author(s):  
Christian Arenz ◽  
Daniel Burgarth ◽  
Robin Hillier
Keyword(s):  
Continuous Variable ◽  
Dynamical Decoupling

scholarly journals Uniaxial Dynamical Decoupling for an Open Quantum System

2019 ◽  
Vol 122 (1) ◽  
Author(s):  
Qi Yao ◽  
Jun Zhang ◽  
Xiao-Feng Yi ◽  
Li You ◽  
Wenxian Zhang
Keyword(s):  
Quantum System ◽  
Open Quantum System ◽  
Dynamical Decoupling ◽  
Open Quantum

The growth of mica polytypes as studied by conventional and high-resolution TEM

1983 ◽  
Vol 41 ◽  
pp. 174-177
Author(s):  
A. Baronnet ◽  
M. Amouric
Keyword(s):  
Water Pressure ◽  
Point Of View ◽  
Temperature Fields ◽  
Natural Occurrence ◽  
Growth Mechanisms ◽  
Long Period ◽  
High Resolution Tem ◽  
Layer Stacking ◽  
Experimental Works ◽  
Potential Use

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.

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