- #1
sherumann
- 2
- 0
Hi. What I'm trying to do is to obtain the energy spectrum from the following dispersion relation:
[tex]E^4-A·E^3+B·E^2-C·E+D-F·E^2·cos(k·a_0)^2+G·E·cos(k·a_0)^2-H·cos(k·a_0)^2 = 0[/tex]
where E is the energy, k is the wave vector and a0 the distance between adjacent neighbors in a 1-Dimensional lattice with a two-atom basis, with some weird on-site energies.
Given the following model parameters:
A = -48.37528081
B = +877.6426691
C = -7077.321036
D = +21403.79575
F = -0.00002232761528
G = +0.0005479196789
H = -0.003361487230
I keep getting imaginary energies! What I do is simply solve the equation for E given some values for k. Am I doing it wrong? Or the parameters must be wrong? Please help! :(
[tex]E^4-A·E^3+B·E^2-C·E+D-F·E^2·cos(k·a_0)^2+G·E·cos(k·a_0)^2-H·cos(k·a_0)^2 = 0[/tex]
where E is the energy, k is the wave vector and a0 the distance between adjacent neighbors in a 1-Dimensional lattice with a two-atom basis, with some weird on-site energies.
Given the following model parameters:
A = -48.37528081
B = +877.6426691
C = -7077.321036
D = +21403.79575
F = -0.00002232761528
G = +0.0005479196789
H = -0.003361487230
I keep getting imaginary energies! What I do is simply solve the equation for E given some values for k. Am I doing it wrong? Or the parameters must be wrong? Please help! :(