I haven't got a feeling about Floquet quasienergy, although it is talked by many people these days.
Floquet theorem:
Consider a Hamiltonian which is time periodic H(t)=H(t+τ). The Floquet theorem says the solution to the Schrödinger equation will have the form
ψ(r,t)=e−iεtu(r,t) ,
where u(r,t) is a function periodic in time.
We can rewrite the Schrödinger equation as
Hu(r,t)=[H(t)−iℏ∂∂t]u(r,t)=εu(r,t) ,
the H can be thought as a Hermitian operator in the Hilbert space R+T, where T is a Hilbert space with all square integrable periodic functions with periodicity τ. Then the above equation can be thought analogy to the stationary Schrödinger equation, with the real eigenvalue ε defined as Floquet quasienergy.
My question is, since in stationary Schrödinger equation, we have continuous and discrete spectrum. How about floquet quasienergy?
Another thing is, is this a measurable quantity? If it is, in what sense it is measurable? (I mean, in the stationary case, the eigenenergy difference is a gauge invariant quantity, what about quasienergy?)
This post imported from StackExchange Physics at 2014-10-07 10:52 (UTC), posted by SE-user luming