Modified thermodynamics as an approach to the description of some universal properties of "nearly perfect fluids"

We show that the quantum statistical mechanics describing quantum and thermal properties of objects has only the sense of a particular semiclassical approximation. We propose a more general (than that theory) microdescription of objects in a heat bath taking a vacuum into account as an object environment; we call it (h k)-dynamics (hk D). We introduce a new generative operator, a Schrödingerian or a stochastic action operator, and will show its fundamental role in the determination of such macroquantities as internal energy, effective temperature, and effective entropy. We establish that hkD can serve as an initial microtheory for constructing a modified thermodynamics. On this ground, we can explain the universality of the ratio "effective action to effective entropy" at zero temperature and its minimal value in the form h/2k. This result corresponds to experimental data obtained recently under studying a new matter state - a nearly perfect fluid. © 2010

Quantum-mechanical analog of the zeroth law of thermodynamics (to the problem of incorporating thermodynamics into the quantum-mechanical theory)

The presented approach to incorporate the stochastic thermodynamics into the quantum theory is based on the idea, proposed earlier by the authors, to consistently consider the stochastic influence by the environment considered as the whole and described by the wave functions of arbitrary vacua. In this research, a possibility of the explicit incorporation of the zeroth law of stochastic thermodynamics into the quantum-mechanical theory in the form of the saturated Schr̈odinger uncertainty relation is realized. This allows a comparative analysis between the sets of arbitrary vacuum states, namely, squeezed coherent (SCSs) and correlated coherent (CCSs) states, to be carried out. A possibility to establish a relation between SCSs and CCSs, on the one hand, and thermal states, on the other hand, is discussed. © A.D. SUKHANOV, O.N. GOLUBEVA, V.G. BAR'YAKHTAR, 2013

Modified thermodynamics as an approach to the description of some universal properties of "nearly perfect fluids"

We show that the quantum statistical mechanics describing quantum and thermal properties of objects has only the sense of a particular semiclassical approximation. We propose a more general (than that theory) microdescription of objects in a heat bath taking a vacuum into account as an object environment; we call it (h k)-dynamics (hk D). We introduce a new generative operator, a Schrödingerian or a stochastic action operator, and will show its fundamental role in the determination of such macroquantities as internal energy, effective temperature, and effective entropy. We establish that hkD can serve as an initial microtheory for constructing a modified thermodynamics. On this ground, we can explain the universality of the ratio "effective action to effective entropy" at zero temperature and its minimal value in the form h/2k. This result corresponds to experimental data obtained recently under studying a new matter state - a nearly perfect fluid. © 2010

Quantum-mechanical analog of the zeroth law of thermodynamics (to the problem of incorporating thermodynamics into the quantum-mechanical theory)

The presented approach to incorporate the stochastic thermodynamics into the quantum theory is based on the idea, proposed earlier by the authors, to consistently consider the stochastic influence by the environment considered as the whole and described by the wave functions of arbitrary vacua. In this research, a possibility of the explicit incorporation of the zeroth law of stochastic thermodynamics into the quantum-mechanical theory in the form of the saturated Schr̈odinger uncertainty relation is realized. This allows a comparative analysis between the sets of arbitrary vacuum states, namely, squeezed coherent (SCSs) and correlated coherent (CCSs) states, to be carried out. A possibility to establish a relation between SCSs and CCSs, on the one hand, and thermal states, on the other hand, is discussed. © A.D. SUKHANOV, O.N. GOLUBEVA, V.G. BAR'YAKHTAR, 2013

Phenomenological theory of relaxation in two-sublattice ferrite

The dissipative function of a two-sublattice ferrite was constructed. The relaxation times for the acoustic and optical branches of spin waves are calculated, as well as the relaxation times for the magnetization and antiferromagnetism vectors. The process of antiferromagnetism vector relaxation is shown to be the quickest one. The corresponding relaxation time is governed by the exchange relaxation constant and, due to the exchange interactions between atoms in the sublattices, becomes shorter owing to the dynamics of the antiferromagnetism vector. The process of ferrite magnetization relaxation is the slowest one. In the exchange approximation, the magnetization relaxation time tends to infinity, as the length of magnetization non-uniformities grows. The results obtained are compared with the experimental data on the relaxation phenomenon in GdFeCo alloy of rare-earth and transition metals. © V.G. BAR'YAKHTAR, B.A. IVANOV, O.N. GOLUBJEVA, A.D. SUKHANOV, 2013

A ratio of the shear viscosity to the density of entropy for helium

We have studied the ratio (n/s) of the shear viscosity η to the density of entropy s for helium as a function of the temperature and have established that the minimal value, (n/s)min, satisfies the Kovtun-Son-Starinets inequality, (n/s)min ≥ (h/4ΠKB). © V.G. BAR'YAKHTAR, E.D. BELOKOLOS, O.N. GOLUBEVA, A.D. SUKHANOV, 2014

Upper critical field of Me-Y-Ba-Cu-O (Me=Zr, Hf)

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A ratio of the shear viscosity to the density of entropy for helium

We have studied the ratio (n/s) of the shear viscosity η to the density of entropy s for helium as a function of the temperature and have established that the minimal value, (n/s)min, satisfies the Kovtun-Son-Starinets inequality, (n/s)min ≥ (h/4ΠKB). © V.G. BAR'YAKHTAR, E.D. BELOKOLOS, O.N. GOLUBEVA, A.D. SUKHANOV, 2014

Phenomenological theory of relaxation in two-sublattice ferrite

The dissipative function of a two-sublattice ferrite was constructed. The relaxation times for the acoustic and optical branches of spin waves are calculated, as well as the relaxation times for the magnetization and antiferromagnetism vectors. The process of antiferromagnetism vector relaxation is shown to be the quickest one. The corresponding relaxation time is governed by the exchange relaxation constant and, due to the exchange interactions between atoms in the sublattices, becomes shorter owing to the dynamics of the antiferromagnetism vector. The process of ferrite magnetization relaxation is the slowest one. In the exchange approximation, the magnetization relaxation time tends to infinity, as the length of magnetization non-uniformities grows. The results obtained are compared with the experimental data on the relaxation phenomenon in GdFeCo alloy of rare-earth and transition metals. © V.G. BAR'YAKHTAR, B.A. IVANOV, O.N. GOLUBJEVA, A.D. SUKHANOV, 2013