printf('K(ph)=2*pi/λph\n=ħ*ω/ħ*ν\n=Eg/ħ*ν');   //k-vector of a photon
Eg=(1.5)*(1.6)*(10^-19);
b=(1.05)*(10^-26);  //say (ħ*ν)=b
a=(Eg)/(b);
printf('\nthe k-vector of photon for GaAs will be %f',a);