Abstract:
Low-dimensional systems recently have gained huge amount of scienti c interest
in the eld of nanoscience and nanotechnology because of their unique electronic,
optical and mechanical properties.[1{3] The appearance of interesting novel phenomena
in these materials, many of which are not observed in bulk systems, has
made them really attractive to investigate.[3, 4]
The interesting properties emerge in these systems due to the quantum con-
nement e ects which prevail in low dimensions.[5{7] The motions of microscopic
degrees of freedom of electrons, phonons etc. get constrained due to the reduction
of length scale in these materials. In such a situation, electronic correlations
and restricted boundary conditions introduce various exotic properties in these
materials,[6, 8, 9] e.g., decrease in con ning dimension leads to discrete energy
levels and this, in turn, increases or widens up the band gap of a low dimensional
material.