Photonic crystals in biology

Poster Session, Tuesday, June 15
Theme A1 - B702
Diamagnetic Susceptibility in Quantum Well
Hasan Akbas 1 * and 1
1 Department of Physics, Trakya University, Edirne 22030,Turkey
Abstract-The d iamagnetic susceptibility of a hydrogenic donor placed in Si,Ge,GaAs quantum wells with infinite confinement
potential has been investigated as function of the well sizes using anisotropic effective masses. For the Ge the diamagnetic
susceptibility is found to be
The diamagnetic plays an important roles in optical and
transport phenomena of semiconductor nanostructers. The
optical properties of quantum wells are of significant
importance in possible device applications. A few physical
quantities that depend on the donor wave function directly
are diamagnetic susceptibility, polarizab ility and oscillator
strengths.
In present work, we study a hydrogenic impurity within
an infinite quantum well with anisitropic effective mass of
electron. Therefore, the motion of the electron in the
longitudinal directions is different from that in the
transverse direction.
The aim of this work is to obtain the diamagnetic
susceptibility of the hydrogenic donor and to understand
how the transverse and longitudinal parts of susceptibility
reflect charge in the quantum well size. The calculation of
the donor wawe function are performed using effective
mass approximation within a variational approach.
The Hamiltonian of the hydrogenic donor impurity,
in the cylindrical coordinate system is
(a.u.)
0
-0.04
-0.08
-0.12
-0.16
-0.2
dia
z
0 200 400 600 800 1000
L(A o )
Figure 1. Variation of the transverse, longitudial,
and total susceptibility as function of the well width
for Ge.
where and denote transverse and longitudinal
effective masses of electron , respectively , and is a
static dielectric constant. The confining potential is given
by
The anisotropy destroys spherical symmetry of the
hydrogenic donor. We therefore choose two-parametric
trial wave function of the ground state.
where and are the variational parameters. The ground
state donor binding energy is given by
The diamagnetic susceptibility of the hydrogenic donor
is given by
=
We calculate a binding energy of the hydrogenic donor
with various effective mass anisotropy parameters;
, GaAs , Si and
Ge . Our results of the binding energy agrees
with results in .
The variation of for and
Ge is given in Fig 1.
In case of small , Ge
, total susceptibility is
found to be
Corrresponding author: 0Thasan22ak@yahoo.com
[1] P.Andreev, T.V.Pavlova, PhysicaE 40, 1551,2008,
Hydrogenic impurity states in semiconducting nanostructers with
anisotropic effective mass.
[2]
Microstructures 46 ,817,2009 ,The diamagnetic susceptibilities of
donors in quantum wells anisotropic effective mass.
6th Nanoscience and Nanotechnology Conference, zmir, 2010 313