Physics-Uspekhi 

About: Physics-Uspekhi is an academic journal published by Lebedev Physical Institute. The journal publishes majorly in the area(s): Electron & Laser. It has an ISSN identifier of 1063-7869. Over the lifetime, 6694 publications have been published receiving 151979 citations. The journal is also known as: Physics - Uspekhi.

Unpaired Majorana fermions in quantum wires

Abstract: Certain one-dimensional Fermi systems have an energy gap in the bulk spectrum while boundary states are described by one Majorana operator per boundary point. A finite system of length L possesses two ground states with an energy difference proportional to exp(-L/l0) and different fermionic parities. Such systems can be used as qubits since they are intrinsically immune to decoherence. The property of a system to have boundary Majorana fermions is expressed as a condition on the bulk electron spectrum. The condition is satisfied in the presence of an arbitrary small energy gap induced by proximity of a three-dimensional p-wave superconductor, provided that the normal spectrum has an odd number of Fermi points in each half of the Brillouin zone (each spin component counts separately).

Double-time green functions in statistical physics

Abstract: 1. Introduction 320 2. Double-time temperature-dependent Green functions 321 3. Spectral representations 324 4. Green functions in the theory of irreversible processes 326 5. Perfect quantum gases 328 6. Application to the theory of superconductivity 330 7. Application to the theory of ferromagnetism 336 8. Electron-lattice interaction 338 9.Conclusions 342

Violation of CP invariance, C asymmetry, and baryon asymmetry of the universe

Abstract: This form of notation is connected with the quark concept; we ascribe to the/?, n, and Л quarks n c = + I, and to antiquarks, и,. = — 1. The theory proposes that under laboratory conditions processes involving violation of п в and и д play a negligible role, but they were very important during the earlier stage of the expansion of the universe. We assume that the universe is neutral with respect to the conserved charges (lepton, electric, and combined), but С asymmetrical during the given instant of its development (the positive lepton charge is concentrated in the electrons and the negative lepton charge in the excess of antineutrinos over the neutrinos; the positive electric charge is concentrated in the protons and the negative in the electrons; the positive combined charge is concentrated in the baryons, and the negative in the excess of fi neutrinos over/z antineutrinos). According to our hypothesis, the occurrence of С asymmetry is the consequence of violation of CP in variance in the nonstationary expansion of the hot universe during the superdense stage, as manifest in the difference between the partial probabilities of the charge-conjugate reactions. This effect has not yet been observed experimentally, but its existence is theoretically undisputed (the first concrete example, I, + and 2 _ decay, was pointed out by S. Okubo as early as 1958) and should, in our opinion, have much cosmological significance. We assume that the asymmetry has occurred in an earlier stage of the expansion, in which the particle, energy, and entropy densities, the Hubble constant, and the temperatures were of the order of unity in gravitational units (in conventional units the particle and energy densities were n~ 10

Two-period green's function in statistical physics

Abstract: Various aspects of the application of Green's functions in statistical physics are reviewed, and the future applications of two-period functions (retarding and advancing) are analyzed. The principle properties of the two- period Green's function and their simplest application in irreversible process theory, in the theory of superconductors, in ferromagnetics, and in electron- lattice reactions in common metals and semiconductors are discussed. It is also shown that the causal Green's functions can be successfully replaced with retarding and advancing Green's functions in the analytical expansion of the complex plane. Statistical mechanics sometimes employs the Motsubara temperature Green's functions which are not related to time; however, they are less adaptable than the temperature-time Green's functions. (R.V.J.)