Dominique Persano Adorno - Università di Palermo #
Monte Carlo simulation of the electron spin relaxation process in GaAs 
and Si crystals #
The understanding of the spin-related processes and spin transport in 
GaAs, Si and related compounds is important for solid state physics and 
possible applications of these materials in spintronics. Research in the 
field of spin-electronics are motivated by the possibility to develop 
electronic devices that use the electron spin rather than charge as a 
state variable for processing and storing information. This could allow 
low-power operation and might also have applications in quantum 
computing. However, the utilization of spin polarization as information 
carrier must face the disadvantage that each initial non-equilibrium 
orientation decays over time during the transport. Hence, to open the 
way to implementation of spin-based devices, the features of spin 
relaxation at relatively high temperatures, jointly with the influence 
of transport conditions, should be firstly fully understood and 
interpreted in experiment-related terms, in order to find out the best 
conditions to achieve long spin relaxation times (or spin diffusion 
lengths) in spintronic devices.
In this contribution we show the results of numerical calculations of 
the spin lifetime for conduction electrons drifting in lightly doped 
n-type GaAs or Silicon channels in the presence of static or fluctuating 
electric fields. To model both electronic and spin dynamics and to 
estimate the spin relaxation time, we employ a semiclassical ensemble 
Monte Carlo method. Our findings are in good agreement with those 
obtained by using different theoretical approaches and with the most 
recent experimental results obtained in spin transport devices. 
Moreover, we also show and discuss how spin lifetimes change in a wide 
range of temperature and electric field amplitude, even where 
experimental and/or analytical data are not yet available. From this 
point of view, the results obtained by our Monte Carlo simulations 
represent a guide for future experimental studies and could be very 
useful in a more effective optimization of room-temperature 
semiconductor- based spintronic devices.
<br/>
<br/>
In collaboration with: , N. Pizzolato S. Spezia, C. Graceffa and B. 
Spagnolo