15,918 research outputs found
Does the Equivalence between Gravitational Mass and Energy Survive for a Composite Quantum Body?
We define passive and active gravitational mass operators of the simplest
composite quantum body - a hydrogen atom. Although they do not commute with its
energy operator, the equivalence between the expectation values of passive and
active gravitational masses and energy is shown to survive for stationary
quantum states. In our calculations of passive gravitational mass operator, we
take into account not only kinetic and Coulomb potential energies but also the
so-called relativistic corrections to electron motion in a hydrogen atom.
Inequivalence between passive and active gravitational masses and energy at a
macroscopic level is demonstrated to reveal itself as time dependent
oscillations of the expectation values of the gravitational masses for
superpositions of stationary quantum states. Breakdown of the equivalence
between passive gravitational mass and energy at a microscopic level reveals
itself as unusual electromagnetic radiation, emitted by macroscopic ensemble of
hydrogen atoms, moved by small spacecraft with constant velocity in the Earth's
gravitational field. We suggest the corresponding experiment on the Earth's
orbit to detect this radiation, which would be the first direct experiment
where quantum effects in general relativity are observed.Comment: 10 pages, no figures. arXiv admin note: substantial text overlap with
arXiv:1304.6106, arXiv:1311.2627, arXiv:1205.313
Orbital Effect for the Fulde-Ferrell-Larkin-Ovchinnikov Phase in a Quasi-Two-Dimensional Superconductor in a Parallel Magnetic Field
We theoretically study the orbital destructive effect against
superconductivity in a parallel magnetic field in the
Fulde-Ferrell-Larkin-Ovchinnikov (FFLO or LOFF) phase at zero temperature in a
quasi-two-dimensional (Q2D) conductor. We demonstrate that at zero temperature
a special parameter, , is responsible for strength of
the orbital effect, where is a typical "size" of the
quasi-classical electron orbit in a magnetic field and is the inter-plane
distance. We discuss applications of our results to the existing experiments on
the FFLO phase in the organic Q2D conductors -(ET)Cu(NCS) and
-(ET)Cu[N(CN)]Cl.Comment: 5 pages, 0 figure
Quantum limit in a quasi-one-dimensional conductor in a high tilted magnetic field
Recently, we have suggested Fermi-liquid - non-Fermi-liquid angular
crossovers which may exist in quasi-one-dimensional (Q1D)conductors in high
tilted magnetic fields [see A.G. Lebed, Phys. Rev. Lett. , 157001
(2015).] All calculations in the Letter, were done by using the quasi-classical
Peierls substitution method, whose applicability in high magnetic fields was
questionable. Here, we solve a fully quantum mechanical problem and show that
the main qualitative conclusions of the above mentioned Letter are correct. In
particular, we show that in high magnetic fields, applied along one of the two
main crystallographic axis, we have 2D electron spectrum, whereas, for
directions of high magnetic fields far from the axes, we have 1D electron
spectrum. The later is known to promote non-Fermi-liquid properties. As a
result, we expect the existence of Fermi-liquid - non-Fermi-liquid angular
crossovers or phase transitions. Electronic parameters of Q1D conductor
(Per)Pt(mnt) show that such transitions can appear in feasible high
magnetic fields of the order of .Comment: 4 pages, 0 figure
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