Solutions lecture 7

src/7_tight_binding_model_sol.md

@@ -35,11 +35,11 @@ Group velocity is given as $v=\hbar^{-1}\frac{\partial E}{\partial k}$ with $E=\
 
 ```python
 pyplot.subplot(1,2,1)
-k = np.linspace(-pi/2+0.01, pi/2-0.01, 300)
+k = np.linspace(-pi+0.01, pi-0.01, 300)
 pyplot.plot(k, np.sin(k)/(np.sqrt(1-np.cos(k))));
 pyplot.xlabel('$k$'); pyplot.ylabel('$v(k)$');
-pyplot.xticks([-pi/2, 0, pi/2], [r'$-\pi/2$', 0, r'$\pi/2$']);
-pyplot.yticks([0, 1], [0, r'$2\sqrt{\frac{\kappa}{m}}$']);
+pyplot.xticks([-pi, 0, pi], [r'$-\pi/2$', 0, r'$\pi/2$']);
+pyplot.yticks([-1, 0, 1], [-r'$2\sqrt{\frac{\kappa}{m}}$', 0, r'$2\sqrt{\frac{\kappa}{m}}$']);
 pyplot.tight_layout();
 
 pyplot.subplot(1,2,2)