Tunnel effect

[tolkachev.iv]

Hello ladies and gentlmens.

In this topic i would like to invite people interested in quantum mechanics. Im 4th year bachelor student and would like to know more about the origin of tunnel effect. Why is it happening?

[Sensei]

Tunnel effect or quantum tunneling?

https://en.wikipedia.org/wiki/Tunnel_effect

https://en.wikipedia.org/wiki/Quantum_tunnelling

 

[exchemist]

7 hours ago, tolkachev.iv said:

Hello ladies and gentlmens.

In this topic i would like to invite people interested in quantum mechanics. Im 4th year bachelor student and would like to know more about the origin of tunnel effect. Why is it happening?

Because when a QM entity is confined by a potential barrier, the wave function penetrates the barrier to some extent. The barrier can be thought of as "damping" the wave function progressively to zero. The lower the barrier, the further the wave function penetrates. If the barrier is also sufficiently thin, the wave function may not be damped to zero by the time it reaches the far side. In such a case, that represents a finite probability of detecting the QM entity outside the confining potential barrier.  

[MigL]

There are two ways ( at least ) to look at it.

One is as an uncertainty in the energy, where  the wave function might 'briefly' have enough energy to surmount the potential barrier, to get to the other side in that 'brief' instant.
The other, is that the extent , or position of the wave function allows for some finite probability of a part of it to be on the other side of the potential barrier, if the barrier is not very extensive.
This latter is a re-interpretation of exchemist's previous post.