Quantum tunneling Definition and 131 Threads

I was on another forum and somebody was talking about quantum tunneling and that walking through walls was not impossible. Just highly improbable; the probability of it happening is older than the universe. Some reason it blew my mind away, even though not much was said. Anyone have more insight...

I was wondering about the effect of tunneling of particles in a magnetic field. Classically, a charged particle will whiz around in a circle in a magnetic field, and barring any interruptions, electric fields or gradients in the magnetic field, it'll stay centered around the same magnetic...

Hi. Firstly, can a particle every be found within the potential barrier? I've used the search function to look for an answer for this question, but I didn't really get anything conclusive. However, from what I gather, since there is a probability associated with it being 'found'(meaning it...

From what I read, there is an extremely small probability of one going through a solid wall, according to QM. The chance is so small you might have wait a few lifetimes, or more of the universe to observe it. But how about going very shallowly into the wall? Let's say a few angstroms (Å)...

On pages 23 & 24 of the book Superforce by Paul Davies - The unusual occurances of electrons or other particles as they approach a barrier are described. I would like to know what devices are used in these experiments? What device shoots out electrons or other particles in a single stream...

The probability of finding the particle inside the wall is non-zero, What happen if we do find the particle is inside the wall, would that violate energy conservation? since total energy is smaller than the potential energy of the wall

Wave packets / the wave function is described as the probability density function of a particle, implying that the particle exists exactly at any 1 location at a time according to its associated wave function. This does not make sense to me on many levels, and it seems inconsistent with quantum...

Hi! I have a physics presentation tomorrow where I have to explain how a scanning tunneling microscope works. I also have to explain what quantum tunneling is and how it is used in a scanning tunneling microscope. I've done some research on the internet and I think I have a basic grasp of...

Homework Statement Alpha decay typically involves an alpha-particle of 5-6Mev. How can this be explained using quantum mechanics? Homework Equations The Attempt at a Solution I think I need to work out the potential barrier and then work out how much KE an alpha particle has...

Homework Statement A 10eV electron is incident on a potential barrier of height 25eV and width 1nm. Estimate (order of magnitude) the probability that the electron will tunnel through the barrier, repeat your calculations for a barrier of 01.nm Homework Equations...

I'm trying to wrap my brain around the notion of tunneling and am hoping somebody could be of assistance. I'm wondering about the history of the idea, why was the notion of quantum tunneling first created? (What prompted the idea?) Also, I'd like to find experiments that have shown that...

When a particle tunnels through a finite barrier, does it spontaneously appear on the other side, or does it follow a path through the barrier? If it does the later then does it interact with the barrier? Thanks

I knew of this phenomena prior to , though prior to an e-mail amazon sent me I was unaware of what physicists called it. I have a question regarding the proton demonstration in this clip. Is it possible the electroweak force is acting on the 'tunneling' proton? If, as the commentator is...

Wave functions that produce two lobes of electron probability on opposing sides of the core indicate that our point-like electron must tunnel through the nuclear core when the point charge moves to the opposing lobe. I don't understand what is the driving force for this process? Does this...

Homework Statement When an electron has tunnelled through a potential barrier it's wavefunction is described by a plane wave traveling in the positive x direction. In this region the probability density is constant. I am trying to explain why it is constant but can't find any info in books or...

Homework Statement By using the graph attached, Why high energy alpha particles are emitted by alpha-emitters of short wavelength? Homework Equations Transmission Coefficient Equation : T=exp(-2kd) The Attempt at a Solution Ain't really sure. Can't really figure out why is...

An electron and proton with the same energy E approch a potential barrier whose height V is greater than E. Do they have the same probabilty of getting through? If not, which has a greater probability? Why is that true? So if the electron and proton have the same energy, that means that the...

Gentlemen, The website [PLAIN]www.altair.org[/URL] describes how to create a homebuilt quantum tunneling experiment which I would like to try. It requires the use of a Gunnplexer. If I search for that term, all references to that term seem presuppose more knowledge that I have. Can...

Hi, this is my first post here so apologies for any faux-pas I inadvertly do. Anyways, to the subject at hand. Evanescent Wave Coupling -> abbrv. -> EWC Can someone explain to me evanescent (decaying) waves work? I have been reading a wiki article about EWC, and it made many...

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?

I am trying to understand the PBS NOVA ‘The Ghost Particle’ shown Tuesday 28 February 2006. http://www.pbs.org/wgbh/nova/neutrino/ Question 1 - When neutrinos pass through the Earth interacting in a statistically predictable manner, is this an example of quantum tunneling conforming to a...

Quantum tunneling and other experiments(for experimental experts)... Please read on this website: http://en.wikipedia.org/wiki/Faster-than-light So,what does it mean-does it mean we can start to hope for traveling faster than light? I also found,what some others wrote about this,from other...

Dear Folks: After seeing this Nano-tech forum... Nanalyze Forums - Direct conversion of heat to electricity http://www.nanalyze.com/forums/topic.asp?TOPIC_ID=1006੾ I sent a post to Rodney Cox president of Borealis http://www.powerchips.gi/ (I also asked him about Boeing's patent, and he...

Dear Folks: After seeing this Nano-tech forum... Nanalyze Forums - Direct conversion of heat to electricity http://www.nanalyze.com/forums/topic.asp?TOPIC_ID=1006&#2686 I sent a post to Rodney Cox president of Borealis http://www.powerchips.gi/ (I also asked him about Boeing's...

Recently, I posted a thread on theories on teleportation:https://www.physicsforums.com/showthread.php?t=44179I discussed about how the transporter in Star Trek operates and why it would never work. Any procedure that convert matter to energy would be deadly and reconstruct person from this...

some say that quantum tunneling would act sortof like a hyperspace/warp thing. any views on what it actually is?

Can somebody explain quantum tunneling to me? And the thing about why amplitudes when they are trapped, the energies must choose from a distinct set of values? And why when particles that are totally free to wander will have any energy that they like? Also, why in the atomic spectra, more...

Hi everyone! I'm having some problem calculating the probability for a particle to penetrate a barrier (potential well). This is a math assignment in school, and we haven't learned anything about this area, so I may be fumbling in the dark completely. Anyway, we have the Schrödinger...

Richard.P.Feynman once said "I think it would be safe for me to say that no one in this world understands Quantum Mechanics". Such an amazing theory Quantum Mechanics is, yet hard to understand. Quantum Tunneling has always been given in small portions of many textbooks and details have not been...

If there were a way to isolate a macro-sized object so that it fell under the heisenburg uncertainty rule, and then the wave function for the whole object would "un-collapse", do you think it would be possible to use this as a mode of transportation? When we see electrons move from one position...

What is quantum tunneling?