7,564 research outputs found
Transverse tunneling current through guanine traps in DNA
The current - voltage dependence of the transverse tunneling current through
the electron or hole traps in a DNA is investigated. The hopping of the charge
between the sites of the trap and the charge-phonon coupling results in a
staircase structure of the I-V curve. For typical parameters of the DNA
molecule the energy characteristics of a DNA trap can be extracted from the I-V
dependence, viz., for a small gate voltage the phonon frequency and for a large
gate voltage the hopping integral can be found from the positions of the steps
in the I-V curve. Formation of the polaronic state also results in the
redistribution of the tunneling current between the different sites of the
traps
Temperature dependence of spin polarizations at higher Landau Levels
We report our results on temperature dependence of spin polarizations at
in the lowest as well as in the next higher Landau level that compare
well with recent experimental results. At , except having a much smaller
magnitude the behavior of spin polarization is not much influenced by higher
Landau levels. In sharp contrast, for filling factor we predict
that unlike the case of the system remains fully spin polarized
even at vanishingly small Zeeman energies.Comment: 4 pages, REVTEX, and 3 .ps files, To be published in Physical Review
Letter
Analytic Coulomb matrix elements in a three-dimensional geometry
Using a complete basis set we have obtained an analytic expression for the
matrix elements of the Coulomb interaction. These matrix elements are written
in a closed form. We have used the basis set of the three-dimensional isotropic
quantum armonic oscillator in order to develop our calculations, which can be
useful when treating interactions in localized systems.Comment: 3 pages, errat
Topological entropy of realistic quantum Hall wave functions
The entanglement entropy of the incompressible states of a realistic quantum
Hall system are studied by direct diagonalization. The subdominant term to the
area law, the topological entanglement entropy, which is believed to carry
information about topologic order in the ground state, was extracted for
filling factors 1/3, 1/5 and 5/2. The results for 1/3 and 1/5 are consistent
with the topological entanglement entropy for the Laughlin wave function. The
5/2 state exhibits a topological entanglement entropy consistent with the
Moore-Read wave function.Comment: 6 pages, 6 figures; improved computations and graphics; added
reference
On the MHD load and the MHD metage
In analogy with the load and the metage in hydrodynamics, we define
magnetohydrodynamic load and magnetohydrodynamic metage in the case of
magnetofluids. They can be used to write the magnetic field in MHD in Clebsch's
form. We show how these two concepts can be utilised to derive the magnetic
analogue of the Ertel's theorem and also, how in the presence of non-trivial
topology of the magnetic field in the magnetofluid one may associate the
linking number of the magnetic field lines with the invariant MHD loads. The
paper illustrates that the symmetry translation of the MHD metage in the
corresponding label space generates the conservation of cross helicity.Comment: Some issues in the paper are yet to be addressed. Constructive
critisicms are most welcom
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