Here, an electron is tunneling through a potential barrier (The total energy of the electron is less than the potential barrier).
So the math works out pretty well and we find that the wave function has a finite value on the left of the barrier, inside the barrier and also to the right of the barrier.
I'm unable to grasp what is actually happening inside the barrier though:
Like if I make a measurement and the particle turns out to be inside the barrier (it can since the wave function is finite over there), then will we find it there with negative kinetic energy (since potential is greater than total energy)?
Could you explain what actually happens? Do we find it with negative KE and if so, then what does this even imply physically?
Or does the particle get extra energy from somewhere and we find it with non-negative KE and if so, where does it get the energy from?