Re: Quantum states from classical states?

> And every quantum state can be written as a superposition of coherent
> states, though not in a unique way. Thus the view of quantums states as
> superposition of classical (i.e., coherent) states is fully valid.

The distinction between classical and quantum states can be very nicely
formalized when one looks at the general, i.e. mixed states of a
canonically quantized system. Then one finds that indeed there are
states which behave like classical (the only ad hoc assumption being
that one uses normally ordered operators when calculating averages). If
anybody wants to learn more about how to distinct those states, he may
want to take a look at Phys. Rev. Lett. 94, 153601 (2005)

> Of course, under a sufficiemtly nontrivial quantum dynamics,
> a coherent state does not remain coherent as time develops;
> this explains the departure from classicality in quantum mechanics.

To be more precise, only hamiltonians at most quadratic in x, p leave
coherent states invariant.

Best,
jarek

.

Relevant Pages

  • Re: Quantum states from classical states?
    ... >> And every quantum state can be written as a superposition of coherent ... >> this explains the departure from classicality in quantum mechanics. ... Wigner distributions include coherent states, squeezed coherent states, ...
    (sci.physics.research)
  • Re: Quantum states from classical states?
    ... A quantum state may be viewed as the sum over all possible ... formalism is practical, the Lagrangian formalism offers greater insight ... path with a weight of the form expwhere S is the classical ... So it is alright to imagine a quantum state as a superposition of all ...
    (sci.physics.research)
  • Quantum states from classical states?
    ... Is there a legitimate way to define a quantum state as some kind of ... superposition of classical states? ... Prev by Date: ...
    (sci.physics.research)