Thursday, 11 May 2017

quantum mechanics - Which types of particles are affected by the wave-particle duality?


If we take the double slit experiment as a way of demonstrating the wave-particle duality, which types of particles would show an interference pattern?


For example, I know that electrons show such a pattern. But do protons, too? What about atoms? Where is the boundary between "wavey particles" and "classical particles"?



Answer




All of them. Even molecules show their wave-like nature, as does, in principle, every object. Speaking of these topics an interesting read about diffraction of C60 molecules is: http://www.univie.ac.at/qfp/research/matterwave/c60/


The point is that the wave-like nature of objects can only be observed at lengths comparable the object's De Broglie wavelength, defined by:


$$ \lambda = \frac{h}{p} $$


where $h$ is the Planck constant and $p$ is the object momentum. For an object moving at non-relativistic speeds you may remember that the momentum is defined as $\vec{p}=m\vec{v}$; the De Broglie wavelength is then inversely proportional to the object mass. The bigger an object is, the less relevant its wave-like nature is, and that's why in everyday experience we are not used to observing the wave-like nature of massive objects.


No comments:

Post a Comment

Understanding Stagnation point in pitot fluid

What is stagnation point in fluid mechanics. At the open end of the pitot tube the velocity of the fluid becomes zero.But that should result...