Kubo formula
From Wikipedia, the free encyclopedia
The Kubo formula, named for Ryogo Kubo who first presented the formula in 1957,[1][2] is an equation which expresses the linear response of an observable quantity due to a time-dependent perturbation.
Among numerous applications of the Kubo formula, one can calculate the charge and spin susceptibilities of systems of electrons in response to applied electric and magnetic fields. Responses to external mechanical forces and vibrations can be calculated as well.