# Calculation of polarization coefficient with perturbation.

1. Mar 7, 2012

### yasef

If we have a charged particle, The dipole moment is defined as P=q<r>. Consider a charged particle in the ground state of a !D square well.

V(x)= {0, IxI < L (otherwise ∞)

Clearly P is 0 in the ground state. Another quantity we define is polarizability , which is defşned as P=E where Eis the electric field applied. Calculate for the ground state the 1D well. [ when E is applied we get a perturbation V= -qEr, find the charge in the wavefunction to 1st order in E and calculate P ]