- #1

nuclearpasta

- 4

- 0

Code:

```
f[kx_, ky_,
t_] := -t E^(-I kx a) (1 + 2 E^(I (3 kx a)/2)*Cos[Sqrt[3]/2 ky a]);
GrapheneHam[kx_, ky_, t_] :=
ComplexExpand[{{0, f[kx, ky, t]}, {Conjugate[f[kx, ky, t]], 0}}];
Energies[kx_, ky_, t_] := Eigenvalues[GrapheneHam[kx,ky,t]];
Plot3D[Energies[kx,ky, 2.8], {kx, -Pi/a, Pi/a},{ky, -Pi/a, Pi/a}]
```

In this case the variable a is set to 2.46. Would anyone know if there is something in the syntax I am doing incorrectly, or perhaps the dispersion is being calculated wrong? Any help is appreciated. Thanks!