37,666 research outputs found
Exact solutions of the (2+1) Dimensional Dirac equation in a constant magnetic field in the presence of a minimal length
We study the (2+1) dimensional Dirac equation in an homogeneous magnetic
field (relativistic Landau problem) within a minimal length, or generalized
uncertainty principle -GUP-, scenario. We derive exact solutions for a given
explicit representation of the GUP and provide expressions of the wave
functions in the momentum representation. We find that in the minimal length
case the degeneracy of the states is modified and that there are states that do
not exist in the ordinary quantum mechanics limit (\beta -->0). We also discuss
the mass-less case which may find application in describing the behavior of
charged fermions in new materials like Graphene.Comment: 9 pages, to appear in Physical Review
Initial development of an ablative leading edge for the space shuttle orbiter
A state-of-the-art preliminary design for typical wing areas is developed. Seven medium-density ablators (with/without honeycomb, flown on Apollo, Prime, X15A2) are evaluated. The screening tests include: (1) leading-edge models sequentially subjected to ascent heating, cold soak, entry heating, post-entry pressure fluctuations, and touchdown shock, and (2) virgin/charred models subjected to bondline strains. Two honeycomb reinforced 30 pcf elastomeric ablators were selected. Roughness/recession degradation of low speed aerodynamics appears acceptable. The design, including attachments, substructure and joints, is presented
Separation of variables for a lattice integrable system and the inverse problem
We investigate the relation between the local variables of a discrete
integrable lattice system and the corresponding separation variables, derived
from the associated spectral curve. In particular, we have shown how the
inverse transformation from the separation variables to the discrete lattice
variables may be factorised as a sequence of canonical transformations,
following the procedure outlined by Kuznetsov.Comment: 14 pages. submitted for publicatio
Lambda hyperonic effect on the normal driplines
A generalized mass formula is used to calculate the neutron and proton drip
lines of normal and lambda hypernuclei treating non-strange and strange nuclei
on the same footing. Calculations suggest existence of several bound
hypernuclei whose normal cores are unbound. Addition of Lambda or,
Lambda-Lambda hyperon(s) to a normal nucleus is found to cause shifts of the
neutron and proton driplines from their conventional limits.Comment: 6 pages, 4 tables, 0 figur
Studies on Magnetic-field induced first-order transitions
We shall discuss magnetization and transport measurements in materials
exhibiting a broad first-order transition. The phase transitions would be
caused by varying magnetic field as well as by varying temperature, and we
concentrate on ferromagnetic to antiferromagnetic transitions in magnetic
materials. We distinguish between metastable supercooled phases and metastable
glassy phase.Comment: 50th Golden Jubilee Solid State Physics Symposium during Dec.5-9
(2005) in Mumbai - manuscript of Invited tal
On zero energy states in graphene
[[abstract]]We obtain zero energy states in graphene for a number of potentials and discuss the relation of the decoupled Schr¨odinger-like equations for the spinor components with non-relativistic PT symmetric quantum mechanics.[[notice]]補æ£å®Œ
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