But we are not to take a mutual potential of electron - hole pair into the Hamiltonian .
Now we 're thinking about the effective mass equation for the relative motion of electron hole pair when the external field is applied to a crystal .
We are not to take a mutual potential of electron - hole pair into the Hamiltonian .
Now we 're thinking about the effective mass equation for the relative motion of electron hole pair when the external field is applied to a crystal .