A simple variational method for excited states of coupled anharmonic oscillators

A simple variational method for excited states is presented and extended to handle two-body Hamiltonians. The method is applied to coupled anharmonic oscillators with arbitrary coupling strength. Our results for the ground and excited states are in good agreement with other available results. For n → ∞, a simple but accurate analytical expression for the energy levels is obtained. Our method can also be used to calculate the excited states of other Hamiltonians.link_to_subscribed_fulltex