scholarly journals Quantum-Heat Fluctuation Relations in Three-Level Systems Under Projective Measurements

2020 ◽  
Vol 5 (1) ◽  
pp. 17 ◽  
Author(s):  
Guido Giachetti ◽  
Stefano Gherardini ◽  
Andrea Trombettoni ◽  
Stefano Ruffo
Keyword(s):  
Energy Scale ◽  
Quantum Measurements ◽  
Thermal Component ◽  
Initial State ◽  
Fluctuation Relations ◽  
N Level ◽  
Two Level Systems ◽  
Jarzynski Equality ◽  
Projective Measurements

We study the statistics of energy fluctuations in a three-level quantum system subject to a sequence of projective quantum measurements. We check that, as expected, the quantum Jarzynski equality holds provided that the initial state is thermal. The latter condition is trivially satisfied for two-level systems, while this is generally no longer true for N-level systems, with N > 2 . Focusing on three-level systems, we discuss the occurrence of a unique energy scale factor β eff that formally plays the role of an effective inverse temperature in the Jarzynski equality. To this aim, we introduce a suitable parametrization of the initial state in terms of a thermal and a non-thermal component. We determine the value of β eff for a large number of measurements and study its dependence on the initial state. Our predictions could be checked experimentally in quantum optics.

THE VAN HOVE SINGULARITY IN HIGH Tc SUPERCONDUCTORS

1995 ◽  
Vol 09 (09) ◽  
pp. 1067-1080 ◽  
Author(s):  
M.L. HORBACH ◽  
H. KAJÜTER
Keyword(s):  
Energy Scale ◽  
Measured Temperature ◽  
Van Hove Singularity ◽  
High Tc Superconductors ◽  
Electronic Density ◽  
High Tc ◽  
Scattering Rate ◽  
Weakly Coupled ◽  
Coherence Lengths

Experimental indications for the role of the van Hove singularity (vHs) in the electronic density of states of high Tc superconductors are discussed. It is argued that (i) like the resistivity, the measured temperature and doping dependences of the normal state electronic specific heat of YBCO are consistent with the existence of a vHs and (ii) the doping dependence of Tc in the underdoped and optimally doped regimes may be accounted for mainly by a vHs. Further, we discuss the suppression of the quasiparticle scattering rate below Tc, and the coherence lengths in the hole-doped materials and NCCO. Assuming that the same mechanism for superconductivity operates in the electron-doped and the hole-doped cuprates, we argue that the bosonic mode that causes the superconductivity is strongly influenced by the doping in the overdoped regime. We further argue that this boson involves an energy scale larger than that of phonons and is only weakly coupled to the charge carriers.

Theoretical study of Zeno and anti-Zeno effects on photodissociation dynamics: A model approach

2016 ◽  
Vol 15 (08) ◽  
pp. 1650070 ◽  
Author(s):  
Bikram Nath ◽  
Chandan Kumar Mondal
Keyword(s):  
Repeated Measurements ◽  
Time Interval ◽  
Mathematical Tool ◽  
Population Transfer ◽  
Vibrational States ◽  
Initial State ◽  
Zeno Effect ◽  
Dissociation Dynamics ◽  
Vibrational Population

Zeno and anti-Zeno effects in the evolution of the multi-photonic dissociation dynamics of the diatomic molecule HBr[Formula: see text] owing to repeated measurements demand if the system in the initial state have been studied. The effects have been calculated numerically for the case of vibrational population transfer and dissociation dynamics of HBr[Formula: see text] taking it as a model. We use time-dependent Fourier grid Hamiltonian (TDFGH) method as a mathematical tool in presence of intense radiation field as perturbation. The effects have been explored through a probable mechanism of population transfer from the ground vibrational state to the different upper vibrational states which ultimately go to the dissociation continuum. The results show significant differences in the mechanism of population transfer and the significant role of time interval of measurement ([Formula: see text] in Zeno and anti-Zeno effects. In case of survival probability of ground vibrational states, there is Zeno effect when the frequency of the laser to which the molecule is submitted is near the vibrational [Formula: see text] to [Formula: see text] resonance, while there is anti-Zeno effect if it is far from this resonance.

Can Quantum Measurements Prevent Change?

2020 ◽  
pp. 166-184
Author(s):  
Gershon Kurizki ◽  
Goren Gordon
Keyword(s):  
Quantum State ◽  
High Probability ◽  
Quantum Measurements ◽  
Repeated Measurements ◽  
Quantum Zeno Effect ◽  
Initial State ◽  
Zeno Effect

In a strange dream, Henry is coherently transported towards his bride down the aisle. But just as a small portion of him arrives next to her, that portion disappears in a flash of light caused by a snapshot! Henry keeps trying to be united with his bride, but repeated snapshots cause Henry’s collapse to being far away from her. This dream illustrates the quantum Zeno effect (QZE): if a measurement collapses the quantum state with high probability to the initial state, then frequent repeated measurements can almost stop the change of the quantum state. Yet less frequent measurements cause the opposite, anti-Zeno effect (AZE), whereby change or decay increases. Thus, decay is controllable. These effects confirm Zeno’s argument that change is an illusion, as it is up to the observer to prevent or induce it by appropriate observation. The appendix to this chapter explains the QZE for coherent and decay processes.

Quantum Coherences as a Thermodynamic Potential

2019 ◽  
Vol 26 (04) ◽  
pp. 1950022
Author(s):  
César A. Rodríguez-Rosario ◽  
Thomas Frauenheim ◽  
Alán Aspuru-Guzik
Keyword(s):  
Entropy Production ◽  
Quantum Transport ◽  
Thermodynamic Potential ◽  
Quantum Measurements ◽  
Second Law ◽  
General Sense ◽  
Thermodynamic Potentials ◽  
General Systems ◽  
Thermodynamic Effects

Here we demonstrate how the interplay between quantum coherences and a decoherence bath, such as one given by continuos quantum measurements, lead to new kinds of thermodynamic potentials and flows. We show how a mathematical extension of thermodynamics includes decoherence baths leading to a more general sense of the zeroth and first law. We also show how decoherence adds contributions to the change in entropy production in the second law. We derive a thermodynamic potential that depends only on the interplay between quantum coherences and a decoherence thermodynamic bath. This leads to novel thermodynamic effects, such as Onsager relationships that depend on quantum coherences. This provides a thermodynamics interpretation of the role of decoherence on quantum transport in very general systems.

Modeling an Explosive Liquid Outflow from High Pressure Thin Tubes and Nozzles

2016 ◽  
Vol 851 ◽  
pp. 377-382
Author(s):  
Raisa Bolotnova ◽  
Andrey Topolnikov ◽  
Valeria Korobchinskaya
Keyword(s):  
Liquid Mixture ◽  
Saturation Temperature ◽  
Cylindrical Tube ◽  
Opening Angle ◽  
Radial Expansion ◽  
Two Dimensional ◽  
Initial State ◽  
Parabolic Form ◽  
Conical Form

To describe the explosive flow in thin tubes the model of vapor-liquid mixture with heat and mass transfer in two-dimensional axisymmetric formulation is employed. The phase transformation is significantly amplified with increasing of initial saturation temperature. The radial expansion of the jet outflow occurs due to the intensification of vaporization from cylindrical to conical form and parabolic form for supercritical initial state. Another problem applied to the outflow of a detonation wave in liquid filled with chemically active gas bubbles from the thin cylindrical tube. Modeling shows the important role of the opening angle of the outflow jet, which can either support the detonation or put it down.

scholarly journals A Generic Model for Quantum Measurements

Entropy ◽  
2019 ◽  
Vol 21 (9) ◽  
pp. 904 ◽  
Author(s):  
Alexia Auffèves ◽  
Philippe Grangier
Keyword(s):  
Quantum Mechanics ◽  
Quantum Measurements ◽  
Generic Model ◽  
Quantum Thermodynamics ◽  
Simple Set ◽  
Algebraic Quantum ◽  
Algebraic Quantum Theory ◽  
Born’S Rule ◽  
The Continuum

In previous articles, we presented a derivation of Born’s rule and unitary transforms in Quantum Mechanics (QM), from a simple set of axioms built upon a physical phenomenology of quantization—physically, the structure of QM results of an interplay between the quantized number of “modalities” accessible to a quantum system, and the continuum of “contexts” required to define these modalities. In the present article, we provide a unified picture of quantum measurements within our approach, and justify further the role of the system–context dichotomy, and of quantum interferences. We also discuss links with stochastic quantum thermodynamics, and with algebraic quantum theory.

Secondary Kinetic Isotope Effects in Bimolecular Nucleophilic Substitutions. V. The Role of the Solvent in the Reaction Between Methyl Iodide and Pyridine

1972 ◽  
Vol 50 (7) ◽  
pp. 982-985 ◽  
Author(s):  
K. T. Leffek ◽  
A. F. Matheson
Keyword(s):  
Transition State ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
State Structure ◽  
Transition State Structure ◽  
Initial State ◽  
Nucleophilic Substitutions ◽  
Kinetic Isotope ◽  
Deuterium Isotope Effects

Secondary kinetic deuterium isotope effects are presented for the reaction of methyl-d3 iodide and pyridine in four different solvents. Calculations on mass and moment of inertia change with deuteration in the initial state and an assumed tetrahedral transition state, together with internal rotational effects, are used to rationalize the inverse isotope effects. It is concluded from the variation of the isotopic rate ratio, that the transition state structure varies with solvent.

scholarly journals Real-time broadening of nonequilibrium density profiles and the role of the specific initial-state realization

2017 ◽  
Vol 95 (3) ◽  
Author(s):  
R. Steinigeweg ◽  
F. Jin ◽  
D. Schmidtke ◽  
H. De Raedt ◽  
K. Michielsen ◽  
...  
Keyword(s):  
Real Time ◽  
Initial State ◽  
Density Profiles
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