2,608 research outputs found
Non-equilibrium reversible dynamics of work production in four-spin system in a magnetic field
A closed system of the equations for the local Bloch vectors and spin
correlation functions is obtained by decomplexification of the Liouville-von
Neumann equation for 4 magnetic particles with the exchange interaction that
takes place in an arbitrary time-dependent external magnetic field. The
analytical and numerical analysis of the quantum thermodynamic variables is
carried out depending on separable mixed initial state and the magnetic field
modulation. Under unitary evolution, non-equilibrium reversible dynamics of
power production in the finite environment is investigated.Comment: 12 pages, 3 figures, published version, title change
Dynamic equations for three different qudits in a magnetic field
A closed system of equations for the local Bloch vectors and spin correlation
functions of three magnetic qudits, which are in an arbitrary, time-dependent,
external magnetic field, is obtained using decomplexification of the
Liouville-von Neumann equation. The algorithm of the derivation of the dynamic
equations is presented. In the basis convenient for the important physical
applications structure constants of algebra su(2S+1) are calculated.Comment: 11 page
Josephson Effect in Pb/I/NbSe2 Scanning Tunneling Microscope Junctions
We have developed a method for the reproducible fabrication of
superconducting scanning tunneling microscope (STM) tips. We use these tips to
form superconductor/insulator/superconductor tunnel junctions with the STM tip
as one of the electrodes. We show that such junctions exhibit fluctuation
dominated Josephson effects, and describe how the Josephson product IcRn can be
inferred from the junctions' tunneling characteristics in this regime. This is
first demonstrated for tunneling into Pb films, and then applied in studies of
single crystals of NbSe2. We find that in NbSe2, IcRn is lower than expected,
which could be attributed to the interplay between superconductivity and the
coexisting charge density wave in this material.Comment: 3 pages, 2 figures. Presented at the New3SC-4 meeting, San Diego,
Jan. 16-21 200
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