Can an electron quantum tunnel inside the potential barrier?

In summary: You need to define what you mean by "resolve". I believe that I didn't use such a word.Please note that I tried to be careful in the response that I wrote then. I simply stated that this observation is consistent with the idea that the electron did pass through the barrier, and that it didn't just disappear on one side and appeared at the other side. However, the nature of what it was doing while inside the barrier is still debatable. So I am hesitant to agree with the claim that it can be "resolved" inside the barrier.Also note that the probability that it can penetrate into the barrier drops exponentially as you go further into the barrier. If you make the barrier thick enough, there will be no appreci
  • #1
Leonardo Muzzi
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TL;DR Summary
When I see explanations for quantum tunneling, the discussion is around the probability of an electron manifesting itself before the potential barrier, and after the potential barrier. However, looking at the curves draw, there is a non-zero probability (the evanescent part of the wave) inside the potential barrier itself. Does that mean the electron can be located inside the barrier? What is the possible physical interpretation for that?
When I see explanations for quantum tunneling, the discussion is around the probability of an electron manifesting itself before the potential barrier, and after the potential barrier. However, looking at the curves draw, there is a non-zero probability (the evanescent part of the wave) inside the potential barrier itself. Does that mean the electron can be located inside the barrier? What is the possible physical interpretation for that?
 
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  • #2
Leonardo Muzzi said:
Summary:: When I see explanations for quantum tunneling, the discussion is around the probability of an electron manifesting itself before the potential barrier, and after the potential barrier. However, looking at the curves draw, there is a non-zero probability (the evanescent part of the wave) inside the potential barrier itself. Does that mean the electron can be located inside the barrier? What is the possible physical interpretation for that?

When I see explanations for quantum tunneling, the discussion is around the probability of an electron manifesting itself before the potential barrier, and after the potential barrier. However, looking at the curves draw, there is a non-zero probability (the evanescent part of the wave) inside the potential barrier itself. Does that mean the electron can be located inside the barrier? What is the possible physical interpretation for that?

Well, what is the problem with the tunneling electron being located inside the barrier as the "physical interpretation"?

There have been quite a few threads on this topic, and this was one of my responses:

https://www.physicsforums.com/threa...like-to-get-an-answer-on.460343/#post-3063909

Zz.
 
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  • #3
ZapperZ said:
Well, what is the problem with the tunneling electron being located inside the barrier as the "physical interpretation"?

There have been quite a few threads on this topic, and this was one of my responses:

https://www.physicsforums.com/threa...like-to-get-an-answer-on.460343/#post-3063909

Zz.

That link is exactly what I was looking for, thanks!
 
  • #4
ZapperZ said:
Well, what is the problem with the tunneling electron being located inside the barrier as the "physical interpretation"?

There have been quite a few threads on this topic, and this was one of my responses:

https://www.physicsforums.com/threa...like-to-get-an-answer-on.460343/#post-3063909

Zz.

OK I understood that explanation. Which brings another question: if the particle can in fact resolve inside the barrier, that probability exists regardless of the with of the barrier. Does that mean that particles can tunnel inside any barrier, regardless of the size of it? Let's say there is an infinite long barrier and the probability amplitude on the other side is zero. The particle could still resolve itself inside the barrier. Would that reasoning be correct?
 
  • #5
Leonardo Muzzi said:
OK I understood that explanation. Which brings another question: if the particle can in fact resolve inside the barrier, that probability exists regardless of the with of the barrier. Does that mean that particles can tunnel inside any barrier, regardless of the size of it? Let's say there is an infinite long barrier and the probability amplitude on the other side is zero. The particle could still resolve itself inside the barrier. Would that reasoning be correct?
If the barrier is "infinitely" long then there is no other side.
 
  • #7
Leonardo Muzzi said:
OK I understood that explanation. Which brings another question: if the particle can in fact resolve inside the barrier, that probability exists regardless of the with of the barrier. Does that mean that particles can tunnel inside any barrier, regardless of the size of it? Let's say there is an infinite long barrier and the probability amplitude on the other side is zero. The particle could still resolve itself inside the barrier. Would that reasoning be correct?

You need to define what you mean by "resolve". I believe that I didn't use such a word.

Please note that I tried to be careful in the response that I wrote then. I simply stated that this observation is consistent with the idea that the electron did pass through the barrier, and that it didn't just disappear on one side and appeared at the other side. However, the nature of what it was doing while inside the barrier is still debatable. So I am hesitant to agree with the claim that it can be "resolved" inside the barrier.

Also note that the probability that it can penetrate into the barrier drops exponentially as you go further into the barrier. If you make the barrier thick enough, there will be no appreciable tunneling. So I don't quite understand that part of your question. The wavefunction doesn't propagate without attenuation inside the barrier.

Zz.
 
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  • #8
PeroK said:
If the barrier is "infinitely" long then there is no other side.

Lol. . . well now, that's simply a one sided statement . . . . :wideeyed:

.
 
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Related to Can an electron quantum tunnel inside the potential barrier?

1. What is quantum tunneling?

Quantum tunneling is a phenomenon in which a particle, such as an electron, can pass through a potential barrier that would normally be impossible to overcome according to classical physics.

2. How does quantum tunneling occur?

In quantum tunneling, the particle behaves as both a particle and a wave. This allows it to "tunnel" through the barrier by passing through regions of low probability, also known as "forbidden zones".

3. Can an electron quantum tunnel inside any potential barrier?

No, the electron can only quantum tunnel through barriers that are thin enough and have a low enough potential energy. The probability of tunneling decreases as the barrier becomes thicker or the potential energy increases.

4. What are some real-world applications of quantum tunneling?

Quantum tunneling is a crucial concept in many technologies, such as scanning tunneling microscopy, tunnel diodes, and flash memory. It also plays a role in nuclear fusion reactions and radioactive decay.

5. Is quantum tunneling a deterministic or probabilistic process?

Quantum tunneling is a probabilistic process, meaning that the exact path of the particle cannot be predicted, but the probability of it tunneling through the barrier can be calculated using quantum mechanics.

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