Go Back   Physics Help Forum > College/University Physics Help > Quantum Physics

Quantum Physics Quantum Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old Dec 3rd 2011, 10:14 AM   #1
Junior Member
 
Join Date: Dec 2011
Posts: 1
Evaluating Source Matrix in an open system

Hi
Would you plz look at the following NEGF eqn for an open system ?
(EI-H-sigma)*psi=S=tau*phi;
or, psi=G*tau*phi;
Here psi is device wavefunction and phi is source wavefunction.

if the system is a long semi infinite 1 D unit cell chain of same potential+effectv mass, can I tell that the wavefunction is also same everywhere?

The reason of why I think so is:
since greens function of every cell in this infinite chain is same (thats why we can recursively solve greens function for contact), and every cell sees the same infinite source to its right-side, each of the cell should have same psi.
Now if I go to evaluate psi of the first cell, I get, from Schrdngr eqn:
psi=G*tau*psi
(looks somewhat similar to the equation: G = inv( EI-H-tau*G*tau' );

However, the above equation for psi is a bit unusual, since it says, the matrix (G*tau) should have a eigenvalue =1, and the corresponding eignvector will be psi. It means, for a given energy, I have to calculate G first, and then see if (G*tau) has any eigenvalue =1. If not, there will be no psi for that Energy.

Isn't it weird? Should it happen for a open system? Am I making wrong idea somewhere? Am I overlooking any phenomenon, such as scattering from left-side coupling for a unit cell?

Actually I need to evaluate the column vector 'S' in Schrodingr eqn for a given energy (S=tau*phi). Please refer me to any formalism of evaluating S.

Thank you.
joysoumitra is offline   Reply With Quote
Reply

  Physics Help Forum > College/University Physics Help > Quantum Physics

Tags
evaluating, matrix, negf, open, source, source matrix, system



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
S-matrix in String Theory. What is it? Korybut Theoretical Physics 6 Nov 27th 2013 02:46 PM
matrix in solid state physics nuaajsh Atomic and Solid State Physics 0 Apr 16th 2013 09:34 PM
Matrix Operator Properties/math gelatinouscactus Quantum Physics 1 Nov 26th 2012 10:37 AM
Matrix representations thefrog Quantum Physics 1 Sep 26th 2010 05:10 AM
Open System: Feeding Argon into a Tank KnHz Advanced Thermodynamics 1 Jul 25th 2009 12:41 PM


Facebook Twitter Google+ RSS Feed