trix.m

来自「求解量子力学的薛定谔方程」· M 代码 · 共 17 行

%> The file <trix.m> calculates the energy as a function of Bloch wave number
%> for a periodic 1D discretized  Schrodinger equation.
%> It also displays the allowed and forbidden energy bands.
%> The Hamiltonian has a diagonal part which is a random vector of variable 
%> strength and constant next-to-diagonal elements allowing 'hopping' between
%> sites (this amplitude is normalized to 1).
%> The whole forms an infinite Jacobi matrix.
%> There is a period which can be chosen, inside the unit cell the diagonal 
%> elements are independent random variables with a rectangular distribution.
%> The transfer matrix of the unit cell is calculated for a range of energies 
%> and hence the Bloch momentum as a function of energy.
%> CHOICE: period (integer) and  relative strength of the diagonal part.
%> See how the allowed bands go to zero with increasing strength, the number 
%> of allowed bands is equal to the period.
%>
%>