The effect of state preparation in a many-body system

2014 ◽  
Vol 92 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Adam Zaman Chaudhry ◽  
Jiangbin Gong

For a quantum system interacting with its environment, the role of state preparation is nontrivial. The reason is that before the state preparation procedure, the system and the environment are correlated. Consequently, the state preparation procedure (which acts on the system) indirectly influences the state of the environment depending on the state preparation. In this paper, we use an experimentally realizable model describing a collection of N two-level atoms coupled to a common environment to investigate the influence of the state preparation procedure. We show that the dynamical map describing the evolution of the open quantum system can depend appreciably on the state preparation procedure. Moreover, this effect can be enhanced by increasing N. Our results should be useful for quantum control and quantum tomography.

2010 ◽  
Vol 10 (1&2) ◽  
pp. 87-96
Author(s):  
J. Nie ◽  
H.C. Fu ◽  
X.X. Yi

We present a new analysis on the quantum control for a quantum system coupled to a quantum probe. This analysis is based on the coherent control for the quantum system and a hypothesis that the probe can be prepared in specified initial states. The results show that a quantum system can be manipulated by probe state-dependent coherent control. In this sense, the present analysis provides a new control scheme which combines the coherent control and state preparation technology.


2011 ◽  
Vol 18 (03) ◽  
pp. 253-260 ◽  
Author(s):  
Kavan Modi

We study preparation of states for open quantum mechanics. For non-Markovian systems that are initially correlated with the environment, the effects of the preparation procedure are nontrivial. This is due to the indirect effects on the state of the environment induced via the correlations with the system and the act of preparation on the system. We give three concrete examples of preparation procedure to elucidate our claims.


Author(s):  
S. V. Kozyrev ◽  
A. A. Mironov ◽  
A. E. Teretenkov ◽  
I. V. Volovich

A three-level quantum system interacting with non-equilibrium environment is investigated. The stationary state of the system is found (both for non-coherent and coherent environment) and relaxation and decoherence to the stationary state is described. The stationary state of the system will be non-equilibrium and will generate flows. We describe the dependence of the flows on the state of the environment. We also discuss application of this model to the problem of quantum photosynthesis, in particular, to the description of flows of excitons and generation of excitonic coherences.


The article presents suggestions and comments on the development of new legislation based on new definitions, improvement of regulatory legal acts and their analysis related to the use of biological resources for scientific purposes and ensuring biological safety. The author analyzes important issues that further develop the theory of environmental law in the field of protection and use of biological resources. On issues related to the use and protection of biological resources, analytical information will be provided on the establishment and effective functioning of scientific institutions, their legal status, biological threats and biological safety.It is argued that biosecurity is an important branch of national security. The role of the environment, the importance of international regulation of the use of genetically modified organisms (GMOs) and their by-products are studied , and a number of environmental legal recommendations related to the COVID-19 pandemic are proposed. The author analyzes digitalization in the field of ecology, As the system of environmental monitoring is an urgent problem that has not yet been solved in the world. Its functionality consists in the accumulation, systematization and analysis of information: about the state of the environment, the causes of changes in the state, the sources and factors of impact, for which the author offers his suggestions.


Author(s):  
I. D. Moore ◽  
S. J. van Enk

A recurring problem in quantum mechanics is to estimate either the state of a quantum system or the measurement operator applied to it. If we wish to estimate both, then the difficulty is that the state and the measurement always appear together: to estimate the state, we must use a measurement; to estimate the measurement operator, we must use a state. The data of such quantum estimation experiments come in the form of measurement frequencies. Ideally, the measured average frequencies can be attributed to an average state and an average measurement operator. If this is not the case, we have correlated state-preparation-and-measurement (SPAM) errors. We extend some tests developed to detect such correlated errors to apply to a cryptographic scenario in which two parties trust their individual states but not the measurement performed on the joint state.


2018 ◽  
Vol 22 (6) ◽  
pp. 44-48
Author(s):  
V.I. Golik ◽  
Yu.V. Dmytrak ◽  
V.S. Sergeev ◽  
V.V. Vernigor

Indicators of pollution in the area of tailing dumps allow us to qualify the environmental situation in them as an emergency. Environmental assessment of the role of tailing dumps allows realizing the costs for ensuring the safe interaction of the facility with the environment. Between the state of the environment of the mining region and the possibilities of technologies for the recovery of mining waste, there are legal links that need to be considered when developing a mechanism for their regulation.


2017 ◽  
pp. 37-48
Author(s):  
Viktor Koziuk ◽  
Yuriy Hayda ◽  
Oksana Shymanska

Introduction. The global trend of urban concentration and the agglomeration effects of production, consumption, capital movements, asset accumulation, and innovation generate the issue of how environmentalism and urbanization correlate. The gradient increase of the technogenic press on the environment from small settlements to large cities causes the shift of research focus from the analysis of the ecological component of the welfare of the state to the environmental component of the welfare of cities. Purpose. The basic hypothesis of the article is the presence of a connection (not always direct linear) between the level of welfare of cities and indicators of the environmental situation in them. It is assumed that the level of well-being (including environmental comfort) has a significant influence on both policy factor and certain non-economic factors of higher demand for environmental standards of life. Also, the purpose of the study is to identify the links between indicators that can be used in modeling the environmental indicator of the welfare state both at the national and local levels. Method Data from the Institute for Strategic Development of the Mori Foundation (Japan) for ranking the largest cities in the world according to the Global Power City Index (GPCI) is used as the information content of the research. The study has used a set of methods for statistical analysis, namely correlation, regression and dispersion ones. Results. The comparison of the ranks of the studied cities by the criterion of the state of the environment and for the GPCI generally indicates a moderate correlation between them (Spirman correlation coefficient rS = 0.440, with rst = 0.396 for p <0.01). This underlines the very important role of the environment of cities in the manifestation of their global "magnetism". The environmental factor, which plays the role of attractiveness of the city, is particularly important from the position of increasing global competition for attracting talent, as well as global aging of the population and reducing the proportion of the productive age population. The assumption that life attractiveness can be significantly conditioned by the environmental factor has been confirmed by the correlation results (Pearson correlation coefficient between the state of the environment and the attractiveness for life in world metropolises r = 0.463, p <0.01) and regression of linear single- and multivariate analysis. It is established that there is no significant linear dependence that between indicators of the environment of cities and their level of economic development. At the same time, a nonlinear regression analysis made it possible to construct several adequate nonlinear models in which the variable, which characterizes the development of the city's economic sector in a complex manner, serves as an independent variable, and a generalized indicator of the state of the environment as a dependent one. The constructed metropolitan matrix of the "economic development-ecology" ratio illustrates that, despite the importance of the urban economic development factor, it is possible to break the "enchanted circle" of poverty and bad ecology, or in other words the inability to generate demand and supply for environmental benefits, on one hand, and realize the environmental preferences of households, on other hand. The shift towards agglomerative concentration of the population and employment is a confirmation of the demand for the expansion of the taxonomy of the welfare state at the expense of an indicator of its ecological state.


2016 ◽  
Vol 93 (2) ◽  
Author(s):  
Pierre Doyeux ◽  
Bruno Leggio ◽  
Riccardo Messina ◽  
Mauro Antezza
Keyword(s):  

2009 ◽  
Vol 08 (02) ◽  
pp. A01 ◽  
Author(s):  
Victoria Wibeck

Assessment of trends in the state of the environment constitutes one important aspect of efforts to achieve environmental sustainability. Assessments are often undertaken via indicators which measure progress towards environmental objectives and interim targets. This paper starts from the assumption that different types of environmental indicators have different implications for the public communication and the societal dialogue about the state of the environment and the measures needed to increase ecological sustainability. The paper concludes that it is important to evaluate environmental indicators on the basis of their communicative potential. It is demonstrated how science-based assessment of progress towards environmental objectives may fulfil different aims. Each of these aims may be linked to particular types of indicators, as well as to particular ideas of how to communicate uncertainties, and to particular views of the role of the public in the system of environmental objectives.


2020 ◽  
Vol 15 (1) ◽  
pp. 142-157 ◽  
Author(s):  
Nicula Virgil ◽  
Spânu Simona

AbstractThe bees were declared the most important living beings on the planet. They act as natural indicators of the state of the environment, protect and maintain ecosystems and contribute to genetic and biotic diversity. Due to its socio-economic and scientific role, beekeeping is an activity that contributes to the development of the rural area. In the analysis we have chosen Hunedoara County, considering its national position and prospects for the development of organic beekeeping. The elaboration of the PESTEL analysis ensures a long-term perspective of the apiculture strategy in Hunedoara County. In order to dispose of bee products (honey, organic honey, pollen, propolis, etc.) in optimal conditions to be marketed both through stores and online, we propose the creation of short chains between a specialized micro-enterprise, tourist pensions that provides food services, restaurants or bars that are located in areas with commercial ford and local beekeeping producers in HNV areas, of which at least one holds certification for organic honey. Beekeeping entrepreneurship can be developed through the actions of beekeepers in the field of promotion, by efficiently selecting possible distribution channels in the country and abroad.


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