the Injection of Spin-Polarized Electrons into a Semiconductor
Dr. Yuriy Pershyn, of Professor Privman's group, is modeling the process
of injection of spin-polarized electrons into a semiconductor in terms
of the drift-diffusion model. The system under investigation is shown
in Figure 1. He calculated the spatial distribution of the electron
spin polarization and found that it can be enhanced at the boundary
between two different semiconductors.
1. Spin-Polarized Electron Injection System
Device Simulation for Spin Polarized Transport
is one possible course of development for modern electronics. See Figures
2 and 3. It is supposed to manipulate current spin-polarization,
which will give an additional degree of freedom for information carriers.
Moreover, electron spin possesses quantum properties, which can be used
for quantum information processing.
3. Model of a 2D Structure
Semion Saykin, of Professor Privman's group, and graduate student Min
Shen, of CAMP Professor Ming-Cheng Cheng's group, are investigating
the influence of spin-orbit interaction on the electron transport. Spin-orbit
interaction provides possible control for spin polarized current (for
example, Datta and Das transistor). Also it can create a strong spin
dephasing mechanism even at the absence of magnetic impurities. Defects
of crystal structure, impurities, and phonons influence the electron
spin polarization and reduce the efficiency of spintronics devices.
treat spin quantum-mechanically, using the density matrix (polarization
vector) description, while treating spatial motion semi-classically
in Monte Carlo simulation to study the electron transport and evolution
of spin polarization in the InGaAs/InAlAs quantum well. See Figure
4. This model can be applied for simulation of steady state for
dynamic regimes of spintronics devices.
4. Evaluation of electron spin polarization
Modeling of Non-Linear Physical Phenomena
Vyacheslav Gorshkov, Professor at the Institute of Physics in the Ukraine
and a member of Professor Privman's group, is an expert in numerical
modeling of non-linear physical phenomena in different branches of science.
In particular, he developed a mathematical model to understand the physical
nature of microwave radiation in electron-hole plasma inside the semiconductors
within strongly crossed magnetic and electric fields.
Dr. Gorshkov has
used numerical experiments to study the processes of micro-drop generation
in liquid metal sources of ions, which are used in the microelectronic
industry for the covering of different materials used in space shuttle
engines of low torque (for accurate orientation of space objects). He
has done a considerable amount of work in the numerical modeling of
different work regimes of powerful CO2-lasers on induced discharge and
of excimer lasers with mixed inert gases. He is collaborating with the
Lawrence Berkeley National Laboratory in the U.S. to develop mathematical
models for non-linear processes in plasma lenses for the focusing of
highly accurate beams of heavy ions. Also he is studying the growth
and aggregation dynamics of nanosize particles in highly concentrated
solutions, and collaborating with the U.S. Air-Force in studying the
properties of optical vortexes in singular wave packets.
Models to Explain Formation Mechanisms of Monodispersed Particles
In addition to
his quantum physics work, Professor Privman and his group are collaborating
with CAMP Professors Egon Matijevic', Michal Borkovec, and Dan Goia
on a project to develop a better understanding of the formation of uniform
nanosize and colloidal particles. This knowledge is essential in numerous
areas of modern technology and medicine, because many properties of
materials (such as optical, magnetic and catalytic) are strongly dependent
on the particle size and shape. Thus in order to produce materials of
predictable and reproducible properties, it is essential to develop
techniques for the preparation of monodispersed particles and to devise
theoretical models to explain the mechanisms of their formation. Documented
evidence shows that a majority of uniform colloids are formed by aggregation
of smaller, nanosized subunits.
This group of researchers
experimentally studied the aggregation process of nanosize precursors
for three representative systems (CdS, Au, Fe2O3).
They identified parameters that control the size distribution and internal
structure. They also developed and implemented a theoretical model predicting
the size selection. The model calculations matched the experimental
For more information
about Professor Privman and his research, you may call him at 315-268-3891
or send email to email@example.com.