The nested for loops use the same variable i, meaning that the outer one doesn't do anything except run through the inner one five times, spending time at it. You can reduce the for loops to just one, with the same result only faster.
There are a couple of ways to see something. If you drop the abs and use
then zoom in to the center of the image, you can see points in a nice pentagon pattern, representing the five wave components. If abs is part of the problem specification (because a density is being modeled or something similar), then there is a large nonzero average for all the elements of abs(Quasi). That leads to a very large DC component in the fft, right at the very center of the image. Hard to see anything else. You can remove the DC component and see a good pattern (after zooming in) with
F = fft2(aQ-mean(mean(aQ)));
Incidentally, although it did not matter in this case, it is best to use
F = fft2(ifftshift(aQ-mean(mean(aQ))));
That's because you constructed the spacial array with x=0, y=0 at the center of the array, and ifftshift puts (0,0) at the corner of the array where fft2 expects it to be.