Beyond the quantum adiabatic approximation: Adiabatic perturbation theory
Beyond the quantum adiabatic approximation: Adiabatic perturbation theory
We introduce a perturbative approach to solving the time-dependent Schr\"odinger equation, named adiabatic perturbation theory (APT), whose zeroth-order term is the quantum adiabatic approximation. The small parameter in the power series expansion of the time-dependent wave function is the inverse of the time it takes to drive the system's Hamiltonian …