Engineering topics

Suslov, M. V.

Publications and source records attributed to Suslov, M. V..

6 records

DOE OSTI2019

Specific Features of the Quantum-Size Effect in Transport Phenomena in Bismuth-Thin Films on Mica Substrates

For bismuth thin films on mica, the dependences of the resistivity, magnetoresistance, and Hall coefficient on the samples thickness are investigated at a temperature of 77 K. Quantum-size oscillations in the electrical and galvanomagnetic properties for films with a thickness of <50 nm are discovered. The charge-carrier free-path length is estimated. The reasons for a deviation in the observed experimental dependences from the simple theory of the quantum-size effect in semimetal films are discussed.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2019

The Hall and Seebeck Effects in Bismuth Thin Films on Mica Substrates in the Temperature Range of 77–300 K

The effects of film thickness and block size on the Hall and Seebeck effects in bismuth films on mica substrates are analyzed using experimental data. A preferential decrease in the electron contribution with a decrease in the film thickness and a preferential decrease in the hole contribution with a decrease in the block size are established. The Hall and Seebeck coefficients are calculated using the classical size effect with regard to carrier scattering at block boundaries and anisotropy of the properties of carriers. In the calculation, the electron and hole mobility components and their concentration in a bismuth single crystal are used and the crystallographic orientation of the film crystal are taken into account. The results of the calculation are in good agreement with the experimental data. It is concluded that the value and sign of the Hall and Seebeck coefficients in bismuth films are determined by the competition of the classical size effect and scattering at block boundaries.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2019

Arrow of time and its reversal on the IBM quantum computer

Uncovering the origin of the “arrow of time” remains a fundamental scientific challenge. Within the framework of statistical physics, this problem was inextricably associated with the second Law of thermodynamics, which declares that entropy growth proceeds from the system’s entanglement with the environment. this poses a question of whether it is possible to develop protocols for circumventing the irreversibility of time and if so to practically implement these protocols. Here we show that, while in nature the complex conjugation needed for time reversal may appear exponentially improbable, one can design a quantum algorithm that includes complex conjugation and thus reverses a given quantum state. Using this algorithm on an IBM quantum computer enables us to experimentally demonstrate a backward time dynamics for an electron scattered on a two-level impurity.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2018

Entropy Dynamics in the System of Interacting Qubits

Here, the classical second law of thermodynamics demands that an isolated system evolves with a nondiminishing entropy. This holds as well in quantum mechanics if the evolution of the energy-isolated system can be described by a unital quantum channel. At the same time, the entropy of a system evolving via a nonunital channel can, in principle, decrease. Here, we analyze the behavior of entropy in the context of the H-theorem. As exemplary phenomena, we discuss the action of a Maxwell demon (MD) operating a qubit and the processes of heating and cooling in a two-qubit system. Further we discuss how small initial correlations between a quantum system and a reservoir affect the entropy increase during the quantum-system evolution.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2017

Thermoelectric power of Bi{sub 92}Sb{sub 8} and Bi{sub 85}Sb{sub 15} thin films

The results of studying the galvanomagnetic and thermoelectric properties of thin block Bi{sub 92}Sb{sub 8} and Bi{sub 85}Sb{sub 15} films on mica and polyimide substrates are presented. The method used for measuring the thermoelectric power allowed us to study the temperature dependence the thermoelectric power, without introducing additional deformations into the substrate–film system. A significant difference in the temperature dependences of the galvanomagnetic and thermoelectric properties of films on mica and polyimide is found. The free charge-carrier concentrations and mobilities in the films on mica and polyimide and levels of the chemical potential for electrons and holes are calculated within the two-band approximation. The difference in the charge-carrier parameters for films on mica and polyimide is associated with strains in the film–substrate system.

36 MATERIALS SCIENCE↗

DOE OSTI2016

H-theorem in quantum physics

Remarkable progress of quantum information theory (QIT) allowed to formulate mathematical theorems for conditions that data-transmitting or data-processing occurs with a non-negative entropy gain. However, relation of these results formulated in terms of entropy gain in quantum channels to temporal evolution of real physical systems is not thoroughly understood. Here we build on the mathematical formalism provided by QIT to formulate the quantum H-theorem in terms of physical observables. We discuss the manifestation of the second law of thermodynamics in quantum physics and uncover special situations where the second law can be violated. Lastly, we further demonstrate that the typical evolution of energy-isolated quantum systems occurs with non-diminishing entropy.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗