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simon009988
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When something tunnels, is it just because of the fact that the wavefunction just decided to randomly pick a place that would be disallowed by classical physics? or is there more to it?
Pengwuino said:In a lamens sense (because that's all i know :rofl: :rofl: :rofl: ), a particle can tunnel through a potential barrier because there is always an uncertainty of it's energy and position. Theres a calculable probability that the particle will tunnel through the barrier because we can't be precisely certain what the particles energy will be. If the potential barrier was higher then the particle's energy + uncertainty, it becomes an infinite potential well and can't tunnel.
In the real world (governed by quantum mechanics) you don’t ask how something works. You calculate the probabilities of possible measurement outcomes on the basis of actual measurement outcomes. If something has a probability greater than zero, it can happen. That's all there is to it.simon009988 said:How does quantum tunneling work?
DaveC426913 said:Tunnelling is a poor description of the phenomenon; it does not actually go through the barrier, nor does it acquire enough energy to go over it.
Simply put, we do not question how it will come to be on the other side; we simply acknowledge that it did.
Q: But how?
A: By behaving according to the rules of QM.
When we look at a wave function of a particle (which will describe where we find it when we go looking for it), we see that part of the wave function continues outside the barrier. Thus, in a small fraction of times when we look for the particle, we will simply find it outside the barrier.
A key concept here, is that we cannot be "continually" looking at the particle. Measurement is an effectively instantaneous event. Best we can do is record where it is when we do look.
Interesting. I'm not surprised at the result, but at the fact it's been done.ZapperZ said:So no, the tunneling phenomenon isn't just "electron on one side - and electron appearing on the other side, and one cannot say anything about what is going on in the middle". We can, and we have evidence that the tunneling process does require the particle to traverse through the barrier itself.
Zz.
Quantum tunneling is a phenomenon in which a particle can pass through a potential barrier even though it does not have enough energy to overcome it. This is possible due to the probabilistic nature of particles on the quantum level, where they can exist in multiple states at the same time.
Quantum tunneling occurs due to the uncertainty principle in quantum mechanics, which states that the position and momentum of a particle cannot be precisely known at the same time. This allows particles to exist in multiple states and have a small probability of passing through a potential barrier.
Quantum tunneling is not directly observable in everyday life, but it has important applications in technology, such as in electronic devices like transistors and tunnel diodes. It also plays a crucial role in nuclear fusion reactions in stars.
Classical tunneling is based on the concept of a particle having enough energy to overcome a potential barrier. In quantum tunneling, however, particles do not need to have enough energy and can pass through barriers due to their probabilistic nature.
Quantum tunneling is a fundamental principle in quantum mechanics and has important implications for quantum computing. It allows for the manipulation of quantum bits (qubits) to perform calculations and solve problems much faster than classical computers.