56 research outputs found
Optimizing edge state transfer in a Su-Schrieffer-Heeger chain via hybrid digital-analog strategies
Su-Schrieffer-Heeger (SSH) chain, serving as a paradigmatic model for
comprehending topological phases and their associated edge states, plays a
pivotal role in advancing our understanding of quantum materials and quantum
information processing and technology. In this paper, we introduce a hybrid
analog-digital protocol designed for the non-adiabatic yet high-fidelity
transfer of edge states in a SSH chain, featuring two sublattices A and B. The
core of our approach lies in harnessing the approximate time-dependent
counter-diabatic (CD) interaction, derived from adiabatic gauge potentials.
However, to enhance transfer fidelity, particularly in long-distance chains,
higher-order nested commutators become crucial. To simplify experimental
implementation and navigate computational complexities, we identify the
next-to-nearest-neighbour (NNN) hopping terms between sublattice A as dominant
CD drivings, and further optimize them by using variational quantum circuits.
Through digital quantum simulation, our protocol showcases the capability to
achieve rapid and robust solutions, even in the presence of disorder. This
analog-digital transfer protocol, an extension of quantum control methodology,
establishes a robust framework for edge state transfer. Importantly, the
optimal CD drivings identified can be seamlessly implemented across various
quantum registers, highlighting the versatility of our approach
Solving Logistic-Oriented Bin Packing Problems Through a Hybrid Quantum-Classical Approach
The Bin Packing Problem is a classic problem with wide industrial
applicability. In fact, the efficient packing of items into bins is one of the
toughest challenges in many logistic corporations and is a critical issue for
reducing storage costs or improving vehicle space allocation. In this work, we
resort to our previously published quantum-classical framework known as
Q4RealBPP, and elaborate on the solving of real-world oriented instances of the
Bin Packing Problem. With this purpose, this paper gravitates on the following
characteristics: i) the existence of heterogeneous bins, ii) the extension of
the framework to solve not only three-dimensional, but also one- and
two-dimensional instances of the problem, iii) requirements for item-bin
associations, and iv) delivery priorities. All these features have been tested
in this paper, as well as the ability of Q4RealBPP to solve real-world oriented
instances.Comment: 7 pages, 7 figures, paper accepted for being presented in the
upcoming 26th IEEE International Conference on Intelligent Transportation
Systems - ITSC 202
Hybrid Approach for Solving Real-World Bin Packing Problem Instances Using Quantum Annealers
Efficient packing of items into bins is a common daily task. Known as Bin
Packing Problem, it has been intensively studied in the field of artificial
intelligence, thanks to the wide interest from industry and logistics. Since
decades, many variants have been proposed, with the three-dimensional Bin
Packing Problem as the closest one to real-world use cases. We introduce a
hybrid quantum-classical framework for solving real-world three-dimensional Bin
Packing Problems (Q4RealBPP), considering different realistic characteristics,
such as: i) package and bin dimensions, ii) overweight restrictions, iii)
affinities among item categories and iv) preferences for item ordering.
Q4RealBPP permits the solving of real-world oriented instances of 3dBPP,
contemplating restrictions well appreciated by industrial and logistics
sectors.Comment: 9 pages, 24 figure
Digital Quantum Simulation and Circuit Learning for the Generation of Coherent States
Coherent states, known as displaced vacuum states, play an important role in quantum information processing, quantum machine learning, and quantum optics. In this article, two ways to digitally prepare coherent states in quantum circuits are introduced. First, we construct the displacement operator by decomposing it into Pauli matrices via ladder operators, i.e., creation and annihilation operators. The high fidelity of the digitally generated coherent states is verified compared with the Poissonian distribution in Fock space. Secondly, by using Variational Quantum Algorithms, we choose different ansatzes to generate coherent states. The quantum resources—such as numbers of quantum gates, layers and iterations—are analyzed for quantum circuit learning. The simulation results show that quantum circuit learning can provide high fidelity on learning coherent states by choosing appropriate ansatzes.This research is funded by the QUANTEK project (ELKARTEK program from the Basque Government, expedient No. KK-2021/00070), the project “BRTA QUANTUM: Hacia una especialización armonizada en tecnologías cuánticas en BRTA” (expedient No. KK-2022/00041)
Solving Systems of Linear Equations: HHL from a Tensor Networks Perspective
We present an algorithm for solving systems of linear equations based on the
HHL algorithm with a novel qudits methodology, a generalization of the qubits
with more states, to reduce the number of gates to be applied and the amount of
resources. Based on this idea, we will perform a quantum-inspired version on
tensor networks, taking advantage of their ability to perform non-unitary
operations such as projection. Finally, we will use this algorithm to obtain a
solution for the harmonic oscillator with an external force, the forced damped
oscillator and the 2D static heat equation differential equations.Comment: 7 pages, 7 figure
Genotypic variations in leaf and whole-plant water use efficiencies are closely related in bread wheat genotypes under well-watered and water-limited conditions during grain filling
Productos tecnológicos como aporte a la informatización/administración y desarrollo local mediado por TIC : proyectos en transferencia
Se resumen diversas experiencias de la modelización y generación de sistemas de información en el marco de un proyecto de I+D orientado a la formación de recursos humanos en el sector de servicios y sistemas informáticos con miras a potenciar el desarrollo local mediado por TIC desde ámbitos de la Universidad. Estos productos software que apoyan la gestión de información en diversos dominios como el turismo, salud, educación, han sido desarrolladosaplicando métodos y herramientas de la Ingeniería del Software
A complete set of nascent transcription rates for yeast genes
The amount of mRNA in a cell is the result of two opposite reactions: transcription and mRNA degradation. These reactions are governed by kinetics laws, and the most regulated step for many genes is the transcription rate. The transcription rate, which is assumed to be exercised mainly at the RNA polymerase recruitment level, can be calculated using the RNA polymerase densities determined either by run-on or immunoprecipitation using specific antibodies. The yeast Saccharomyces cerevisiae is the ideal model organism to generate a complete set of nascent transcription rates that will prove useful for many gene regulation studies. By combining genomic data from both the GRO (Genomic Run-on) and the RNA pol ChIP-on-chip methods we generated a new, more accurate nascent transcription rate dataset. By comparing this dataset with the indirect ones obtained from the mRNA stabilities and mRNA amount datasets, we are able to obtain biological information about posttranscriptional regulation processes and a genomic snapshot of the location of the active transcriptional machinery. We have obtained nascent transcription rates for 4,670 yeast genes. The median RNA polymerase II density in the genes is 0.078 molecules/kb, which corresponds to an average of 0.096 molecules/gene. Most genes have transcription rates of between 2 and 30 mRNAs/hour and less than 1% of yeast genes have >1 RNA polymerase molecule/gene. Histone and ribosomal protein genes are the highest transcribed groups of genes and other than these exceptions the transcription of genes is an infrequent phenomenon in a yeast cell
The Rise and Fall of "Respectable" Spanish Liberalism, 1808-1923: An Explanatory Framework
The article focuses on the reasons behind both the consolidation of what I have termed “respectable” liberalism between the 1830s and the 1840s and its subsequent decline and fall between 1900 and 1923. In understanding both processes I study the links established between “respectable” liberals and propertied elites, the monarchy, and the Church. In the first phase these links served to consolidate the liberal polity. However, they also meant that many tenets of liberal ideology were compromised. Free elections were undermined by the operation of caciquismo, monarchs established a powerful position, and despite the Church hierarchy working with liberalism, the doctrine espoused by much of the Church was still shaped by the Counter-Reformation. Hence, “respectable” liberalism failed to achieve a popular social base. And the liberal order was increasingly denigrated as part of the corrupt “oligarchy” that ruled Spain. Worse still, between 1916 and 1923 the Church, monarch, and the propertied elite increasingly abandoned the liberal Monarchist Restoration. Hence when General Primo de Rivera launched his coup the rug was pulled from under the liberals’ feet and there was no one to cushion the fall
Women's Education Level, Maternal Health Facilities, Abortion Legislation and Maternal Deaths: A Natural Experiment in Chile from 1957 to 2007
The aim of this study was to assess the main factors related to maternal mortality reduction in large time series available in Chile in context of the United Nations' Millennium Development Goals (MDGs).Time series of maternal mortality ratio (MMR) from official data (National Institute of Statistics, 1957-2007) along with parallel time series of education years, income per capita, fertility rate (TFR), birth order, clean water, sanitary sewer, and delivery by skilled attendants were analysed using autoregressive models (ARIMA). Historical changes on the mortality trend including the effect of different educational and maternal health policies implemented in 1965, and legislation that prohibited abortion in 1989 were assessed utilizing segmented regression techniques.During the 50-year study period, the MMR decreased from 293.7 to 18.2/100,000 live births, a decrease of 93.8%. Women's education level modulated the effects of TFR, birth order, delivery by skilled attendants, clean water, and sanitary sewer access. In the fully adjusted model, for every additional year of maternal education there was a corresponding decrease in the MMR of 29.3/100,000 live births. A rapid phase of decline between 1965 and 1981 (-13.29/100,000 live births each year) and a slow phase between 1981 and 2007 (-1.59/100,000 live births each year) were identified. After abortion was prohibited, the MMR decreased from 41.3 to 12.7 per 100,000 live births (-69.2%). The slope of the MMR did not appear to be altered by the change in abortion law.Increasing education level appears to favourably impact the downward trend in the MMR, modulating other key factors such as access and utilization of maternal health facilities, changes in women's reproductive behaviour and improvements of the sanitary system. Consequently, different MDGs can act synergistically to improve maternal health. The reduction in the MMR is not related to the legal status of abortion
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