Localized Wave Packet
In order to have a wave localized in a region of space Dx, it must have a spread of momenta Dp
The smaller Dx, the larger the range Dp required
Leads to the Heisenberg Uncertainty Principle:
Can understand from de Broglie’s Equation
The minimum range Dx is of order the wavelength ?? which requires a range of momenta Dp at least as large as ?p ?x ³ ~h