Saito Group (Open)
Started by Thomas.2013.09.02
This is Thomas's logbook for September of 2013.
1st week [Electron-Photon Interactions]†
- 09.02
- The Hamiltonian for the electron-photon interaction is given by &tex(): Error! The expression contains invalid characters.;, in this equation &tex(): Error! The expression contains invalid characters.; is the linear momentum, &tex(): Error! The expression contains invalid characters.; is the charge of the particle, &tex(): Error! The expression contains invalid characters.; is the vector potential, &tex(): Error! The expression contains invalid characters.; is the particle's mass, &tex(): Error! The expression contains invalid characters.; is the speed of light and &tex(): Error! The expression contains invalid characters.; is the scalar potential. It is possible to check this by using the canonical equations from Hamilton, &tex(): Error! The expression contains invalid characters.; and &tex(): Error! The expression contains invalid characters.;.
- From those last equations together with the following identities &tex(): Error! The expression contains invalid characters.; and &tex(): Error! The expression contains invalid characters.; With all this considered it was possible to arrive at the equation of motion of a particle under an electromagnetic field, &tex(): Error! The expression contains invalid characters.;.
- Consider the wave functions from quantum well, hydrogen atom, and solve with the electromagnetic(electron-photon interaction) perturbation.
- 09.03
- By looking at the previous Hamiltonian in a different shape, &tex(): Error! The expression contains invalid characters.; where the term inside the brackets is actually the unperturbed hamiltonian, and the other terms are the perturbations that arise from the electomagnetic field influence.
- As the electromagnetic field is just a perturbation, it is not so strong, therefore it is possible to disregard &tex(): Error! The expression contains invalid characters.;, and consider the perturbation Hamiltonian as &tex(): Error! The expression contains invalid characters.;.
- Taking a monochromatic wave over a quantum well of length &tex(): Error! The expression contains invalid characters.; it is possible to find the new wavefunction after taking the &tex(): Error! The expression contains invalid characters.;.
- Find the actual new wavefunctions.