7 research outputs found
Bipartite and Tripartite Entanglement of Truncated Harmonic Oscillator Coherent States via Beam Splitters
We introduce a special class of truncated Weyl-Heisenberg algebra and discuss
the corresponding Hilbertian and analytical representations. Subsequently, we
study the effect of a quantum network of beam splitting on coherent states of
this nonlinear class of harmonic oscillators. We particularly focus on quantum
networks involving one and two beam splitters and examine the degree of
bipartite as well as tripartite entanglement using the linear entropy
Dynamical mass generation via space compactification in graphene
Fermions in a graphene sheet behave like massless particles. We show that by
folding the sheet into a tube they acquire non-zero effective mass as they move
along the tube axis. That is, changing the space topology of graphene from 2D
to 1D (space compactification) changes the 2D massless problem into an
effective massive 1D problem. The size of the resulting mass spectrum depends
on the quantized azimuthal frequency and its line spacing is proportional to
the inverse of the tube diameter.Comment: 8 pages, 2 figure
Transport Properties through Double Barrier Structure in Graphene
The mode-dependent transmission of relativistic ballistic massless Dirac
fermion through a graphene based double barrier structure is being investigated
for various barrier parameters. We compare our results with already published
work and point out the relevance of these findings to a systematic study of the
transport properties in double barrier structures. An interesting situation
arises when we set the potential in the leads to zero, then our 2D problem
reduces effectively to a 1D massive Dirac equation with an effective mass
proportional to the quantized wave number along the transverse direction.
Furthermore we have shown that the minimal conductivity and maximal Fano factor
remain insensitive to the ratio between the two potentials V_2/V_1=\alpha.Comment: 18 pages, 12 figures, clarifications and reference added, misprints
corrected. Version to appear in JLT