scholarly journals Full distribution of work done on a quantum system for arbitrary initial states

2015 ◽  
Vol 92 (4) ◽  
Author(s):  
P. Solinas ◽  
S. Gasparinetti
Keyword(s):  
Quantum System ◽  
Initial States ◽  
Work Done

Quantum universality by state distillationIndirect quantum control for finite-dimensional coupled systems

2010 ◽  
Vol 10 (1&2) ◽  
pp. 87-96
Author(s):  
J. Nie ◽  
H.C. Fu ◽  
X.X. Yi
Keyword(s):  
Quantum System ◽  
Quantum Control ◽  
Coherent Control ◽  
Coupled Systems ◽  
Preparation Technology ◽  
State Preparation ◽  
Finite Dimensional ◽  
State Dependent ◽  
Control Scheme ◽  
Initial States

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.

scholarly journals USE OF THE WHIRLIGIG PRINCIPLE FOR STABILIZING THE INITIAL STATES OF SOME CLASSIC AND QUANTUM SYSTEMS

2020 ◽  
pp. 78-81
Author(s):  
V.A. Buts
Keyword(s):  
Quantum System ◽  
Excited States ◽  
Quantum Systems ◽  
Nuclear Systems ◽  
Initial States

It is shown that the whirligig principle can be used for stabilization of the initial states of some classical and quantum systems. This feature of the whirligig principle is demonstrated by simple examples. The most important result of this work is the proof of the fact that the stabilization of the excited states of quantum systems can be realized by acting not on the quantum system itself, but by acting on the states into which the system must go. Potentially, this result can be used to stabilize excited nuclear systems.

scholarly journals Leggett-Garg Inequalities for Quantum Fluctuating Work

Entropy ◽  
2018 ◽  
Vol 20 (3) ◽  
pp. 200 ◽  
Author(s):  
◽  
Keyword(s):  
Quantum System ◽  
Quantum Correlations ◽  
Weak Measurement ◽  
Projective Measurement ◽  
Level System ◽  
Quantum Regime ◽  
Measurement Scheme ◽  
Temporal Correlations ◽  
Classical Thermodynamics ◽  
Work Done

The Leggett-Garg inequalities serve to test whether or not quantum correlations in time can be explained within a classical macrorealistic framework. We apply this test to thermodynamics and derive a set of Leggett-Garg inequalities for the statistics of fluctuating work done on a quantum system unitarily driven in time. It is shown that these inequalities can be violated in a driven two-level system, thereby demonstrating that there exists no general macrorealistic description of quantum work. These violations are shown to emerge within the standard Two-Projective-Measurement scheme as well as for alternative definitions of fluctuating work that are based on weak measurement. Our results elucidate the influences of temporal correlations on work extraction in the quantum regime and highlight a key difference between quantum and classical thermodynamics.

BIEXCITON SQUEEZING DUE TO OPTICAL EXCITON-BIEXCITON CONVERSION

2000 ◽  
Vol 14 (01) ◽  
pp. 91-100 ◽  
Author(s):  
VO TINH ◽  
DO HUU NHA ◽  
NGUYEN BA AN
Keyword(s):  
Quantum System ◽  
Numerical Calculations ◽  
Squeezed State ◽  
Initial States ◽  
Theoretical Results

We theoretically investigate the evolution of biexcitons from a coherent into a squeezed state in a fully quantum system described by a trilinear Hamiltonian allowing the transition "photons + excitons ⇌ biexcitons". Curious dependences of the direction and degree of biexciton squeezing on the initial states of photons and excitons are obtained. The theoretical results are well reproduced by numerical calculations.

scholarly journals Work Done on a Coherently Driven Quantum System

2015 ◽  
Vol 05 (03) ◽  
pp. 89-102
Author(s):  
Issofa Nsangou ◽  
Lukong Cornelius Fai
Keyword(s):  
Quantum System ◽  
Work Done

Feedback control for communication with non-orthogonal states

2007 ◽  
Vol 7 (1&2) ◽  
pp. 127-138
Author(s):  
K. Jacobs
Keyword(s):  
Feedback Control ◽  
Quantum System ◽  
Continuous Measurement ◽  
Information Gain ◽  
Quantum Mechanical ◽  
Optimal Measurement ◽  
Classical Information ◽  
Long Time ◽  
Initial Preparation ◽  
Initial States

Communicating classical information with a quantum system involves the receiver making a measurement on the system so as to distinguish as well as possible the alphabet of states used by the sender. We consider the situation in which this measurement takes an appreciable time. In this case the measurement must be described by a continuous measurement process. We consider a continuous implementation of the optimal measurement for distinguishing between two non-orthogonal states, and show that feedback control can be used during this measurement to increase the rate at which the information regarding the initial preparation is obtained. We show that while the maximum obtainable increase is modest, the effect is purely quantum mechanical in the sense that the enhancement is only possible when the initial states are non-orthogonal. We find further that the enhancement in the rate of information gain is achieved at the expense of reducing the total information which the measurement can extract in the long-time limit.

Social Cognition in Gilles de la Tourette Syndrome

2019 ◽  
Vol 30 (4) ◽  
pp. 243-249
Author(s):  
Ronja Weiblen ◽  
Melanie Jonas ◽  
Sören Krach ◽  
Ulrike M. Krämer
Keyword(s):  
Tourette Syndrome ◽  
Social Cognitive ◽  
Mirror Neuron System ◽  
Mirror Neuron ◽  
Theoretical Work ◽  
Neural Processes ◽  
The Social ◽  
Decision Making System ◽  
Social Decision Making ◽  
Work Done

Abstract. Research on the neural mechanisms underlying Gilles de la Tourette syndrome (GTS) has mostly concentrated on abnormalities in basal ganglia circuits. Recent alternative accounts, however, focused more on social and affective aspects. Individuals with GTS show peculiarities in their social and affective domain, including echophenomena, coprolalia, and nonobscene socially inappropriate behavior. This article reviews the experimental and theoretical work done on the social symptoms of GTS. We discuss the role of different social cognitive and affective functions and associated brain networks, namely, the social-decision-making system, theory-of-mind functions, and the so-called “mirror-neuron” system. Although GTS affects social interactions in many ways, and although the syndrome includes aberrant social behavior, the underlying cognitive, affective, and neural processes remain to be investigated.

Review of methods of slag removal from melt surface in hot metal and steel ladles

2020 ◽  
Vol 76 (12) ◽  
pp. 1243-1252
Author(s):  
B. A. Sivak ◽  
A. V. Protasov ◽  
L. A. Smirnov
Keyword(s):  
Settling Tank ◽  
Necessary Condition ◽  
Hot Metal ◽  
Slag Removal ◽  
Production Scale ◽  
Technical Parameters ◽  
Ecological Requirements ◽  
The Usa ◽  
Work Done ◽  
Technological Methods

The removal of slag from melt surface of hot metal and steel ladles is a necessary condition to provide a deep desulphurization and dephosphorization of hot metal and steel in the process of their processing. A review of methods of slag skimming presented, mainly based on slag mechanical shoveling and its removal out of ladles by vacuum sucking. It was shown, that manipulators design for the slag skimming working instrument moving depends on the production scale, mass of the processed heats, amount and properties of the slag to be removed, production process intensity and ecological requirements. Peculiarities of designs and technical parameters of machines for slag skimming presented, designed by Irkutsk plant of heavy machinery, Scientific and Production Enterprise n.a. M.I. Platov, VNIIMETMASH, Kuznetsk and Novolipetsk steel plants. Technological methods of control of slag composition and physical properties considered, first of all of viscosity and fluidity, which have significant effect on selection of a method of slag skimming. Advantages and drawbacks of actions, aimed at more complete slag removal from metal surface by a scraper noted including bath blowing off by an inert gas, liquid slag tapping into am intermediate settling tank following its removal into a slag bowl. In case of satisfactory fluidity it is possible to slag removal by vacuum sucking, which at the same time promoted the melt degassing. Work done in this area abroad noted. Methods of vacuum slag removal developed in the USA and Japan described.

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