Wavelength in QM

1. Sep 22, 2009

suku

Can anyone tell me how is wavelength defined for a wave associated with a particle?
If the wave function we are speaking of has no physical significance,then how can measure its length?
tks for any rpl

2. Sep 22, 2009

muppet

By "wavelength" in QM one usually means the de Broglie wavelength, defined by
$$\lambda=\frac{h}{p}$$
where p is the momentum of a particle and h is planck's constant.

The wavefunction is neither physically insignificant nor something you measure directly. For a basic introduction to what the wavefunction means, see the library article on wave-particle duality; for a more technical description see that on wave function.