how to understand the Wigner function?
what can we learn from the Wigner function of a state? eg, a nonclassical state, its Wigner function value can be negative. From its value we can distinguish the quantum state and classical state. Could we learn more information from it?
The basic information you can extract from the Wigner function W(x,k) is the probability distribution for a state in certain cross-sections of the phase-space. For instance, by integrating W(x,k) over p you get a probability distribution in x, i.e: p(x) and vice versa you can extract p(k) in the similar manner.
Wigner function is more general then a wave function because it can also describe mixed states.
Also it is useful to think in terms of Wigner function while considering squeezed states and homodyne detection.
But, in experimental practice if you want to verify if your state is non-clasical or not there are simpler ways then finding a full Wigner function of the state. Depending on a state you deal with, you my apply different measures of non-classicality such as Q-Mandel parameter, g^(2) or in continues variables the aforementioned squeezing.
- Badges
- Science topic
- Similar topics
- Philosophy
- Philosophy of Mathematics
- Informality