Questions
Questions raised
- [to Marco Coisson] Suppose we have some unperturbed Hamiltonian, H_0, and we have a magnetic field. We then have a magnetic fied dependent perturbation that has a gauge freedom with A. While the exact *energy states should not be dependent on the gauge, we often use perturbation theory instead to compute first order , second order corrections etc. Each term may actually depend on the gauge. So how do you determine accurately the number of corrections you use based on your gauge freedom? A typical example is showing diamagnetism, using the very gauge used in the slides