Forest FermiGoldenRule Notes

Fermi's Golden rule is used to calculate the probability (per unit time) of a quantum mechanical transition between two quantum states. Although Fermi first coined the term "Golden Rule", Dirac developed most of the machinery.

[math]| M_{i,f}| ^2 = \int \psi_i^{*} H_{pert} \psi_f dv[/math]

where

[math]\psi_i[/math] = initial quantum state of the system

[math]\phi_f[/math] = final quantum state of system after a transition

[math]H_{pert}[/math] = part of the Hamiltonian which is responsible for the transition.

[math]H_0[/math] = Unperturbed ("steady state") Hamiltonian

[math]H_{tot} = H_0 + H_{pert}[/math] = total hamiltonian describing the quantum mechanical system

[math]dv[/math] integration over all space