This simulation shows an electron passing through a thin barrier. In classical mechanics, the electron doesn’t have enough energy to get over the barrier. But everything is probabilistic in quantum mechanics (ie. the real world), so there is a small chance that the electron will travel through the barrier and end up on the other side. This is seen by the wave function splitting after hitting the barrier.

The top graph shows the distribution of position (white) and potential energy (red). The bottom graph shows momentum. The blue and green lines on both graph represents the real and imaginary components of the wavefunction and its Fourier transform.

On the right are the average (〈〉) and standard deviation (Δ) of the position (x) and momentum (p).

Is the amplitude of the wave decreasing over time after passing through the barrier? Maybe I just can’t see it but it looks like it is staying constant

Hey, my physics degree is actually helping me understand something!

That’s really cool, thanks for posting.

This is from a [simulation I made on Khan Academy](https://www.khanacademy.org/computer-programming/quantum-tunnelling/5166410192060416). You can go there and fiddle with the variables if you’re so inclined.

**Description**:

This simulation shows an electron passing through a thin barrier. In classical mechanics, the electron doesn’t have enough energy to get over the barrier. But everything is probabilistic in quantum mechanics (ie. the real world), so there is a small chance that the electron will travel through the barrier and end up on the other side. This is seen by the wave function splitting after hitting the barrier.

The top graph shows the distribution of position (white) and potential energy (red). The bottom graph shows momentum. The blue and green lines on both graph represents the real and imaginary components of the wavefunction and its Fourier transform.

On the right are the average (〈〉) and standard deviation (Δ) of the position (x) and momentum (p).

Check out this video for an animated explanation of quantum tunnelling: https://www.youtube.com/watch?v=RF7dDt3tVmI

THERE SHOULD NEVER BE MORE THAN ONE DOT MORTY

With only a layman’s understanding of quantum tunneling, this gif still kinda fries my brain.

Fucking beautiful.

[mp4 link](https://j.gifs.com/JZJ87y.mp4)

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Lewd

am i supposed to know whats happening?

You can play around with a simulation of this yourself by downloading the java applet at https://phet.colorado.edu/en/simulation/quantum-tunneling

Programmed this myself in c++ which was really fun. In Uni we only ever saw tunneling for plane waves which is pretty boring

Is the amplitude of the wave decreasing over time after passing through the barrier? Maybe I just can’t see it but it looks like it is staying constant