Tunneling Definition and 247 Threads

Suppose someone drops a clock and it tunnels through the Earth. What time will have elapsed according to the clock when it emerges on the other side of the Earth?

Homework Statement I am to show that quantum effects are negligible in: (i) The diffraction of a tennis ball of mass m=0.1 kg moving at a speed of 0.5 m/s by a window of size 1X1.5 m^2 (ii)The tunneling probability for a marble of mass m=5 g moving at a speed of 10 cm/s against a...

in zener tunneling phenomena, are the carriers locally generated or non-locally generated? i.e, should we assume the process as though it were generation of holes in the valence band and electrons in the conduction band? i hope someone could shed some physics on this concept. thanks.

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...

Homework Statement There's two parts. Part A) Find the Probability than an electron will tunnel through a barrier if energy is 0.1 ev less than height of the barrier. Barrier is 1nm. Part B) Find tunneling probability if the barrier is widened to 3 nm.Homework Equations I believe relevant...

correct me if I am wrong, but from what I remember, standard tunneling occurs because of the Heisenberg uncertainty principle. There is some known error in the position of a particle (probably a 3d gaussian distribution centered on the mean and with a standard deviation equal to this error...

Hello, I am trying to learn something about how experimental physics is done. I am very new at it and am looking for experienced guidance. A friend of mine (zapperz) suggested that a good way to measure the effect of a magnetic field on electrons in the tunneling state is to have the...

Just wondering in regards to the potential step, what exactly is it in term of physical substance? If its made up of some or any sort of matter, wouldn't the tunneling be effected by the molecular structure and the distance/gap between the particles?

I am interested in measuring the effects of a magnetic field on an electron in a tunneling state. I know very little about solid state and I have very little experimental experience. In order to learn what is required to perform such an experiment, I thought I would pose my question here...

Hello, I know that electrons will be deflected if they move in a magnetic field. I was wondering if tunneling electrons would be deflected in the opposite direction? plxmny

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...

I am working on a project involving a scanning tunneling microscope, and to move atoms i need an untra high vacuum chamber. Any info you have on UHV or STM would be immensly appreciated.:rolleyes: Thanks

Homework Statement We consider a simple model of alpha decay. Imagine an alpha particle moving around inside a nucleus. When the alpha bounces against the surface of the nucleus, it meets a barrier caused by the attractive nuclear force. The dimensions of this barrier vary a lot from one...

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...

I have seen the mathematical proof of how can a particle tunnel through a barrier of higher potential energy but I was unable to understand what happens to the particle during its motion in the barrier. Can you help me? Can this be one of the probable mechanism of teleportation on which I can...

I am a freshman high school student working on a scanning tunneling microscope for a science fair project. I need to build a vacuum for bottom up capabilities. If anyone can help with the STM or the vacuum it would be greatly appreciated.:rolleyes:

Say I have a particle with a kinetic energy of 5 (in some units). And I have a potential barrier of 10 between 0<x<1 (again, in ome unit system), and 0 elsewhere. According to quantum theory, the partcile may be found between 0 and 1. And in this region, if the energy is conserved (5 = T + 10)...

Evolutionary "tunneling" Consider a specific organism. It initially undergoes a genetic change which is nonbeneficial - even detrimental - to several generations. That intermediary state, however, eventually leads (synergistically with a secondary mutation) to an overall postive adaptation...

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...

Hi, for my integration class I am building a scanning tunnelling microscope (STM). I found some interesting designs and I choose the cheapest one (students are poor) witch uses a unimorph disk. Here is the STM design I plan to build: http://www.geocities.com/spm_stm/". For my class I need to...

Hi, for my integration class I am building a scanning tunnelling microscope (STM). I found some interesting designs and I choose the cheapest one (students are poor) witch uses a unimorph disk. The circuits are not that hard to build but I also need to understand them. I have some knowledge in...

Supposed we have a metal sandwitched between two thin dielectrics. If i contact an electrical voltage on the dielectric, there will be tunneling current due to electron tunneling from the metal across the dielectric. i could attempt to calculate this current from a semiclassical approach using...

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...

I can't work out what I am doing wrong in this question. Anyways, here it is: A 3.0 MeV proton is incident on a potential energy barrier of thickness 10fm and height 10 MeV. What is the transmission coefficient T. And here is what I have tried: T=e^(-2bL) b=\sqrt{\frac{8\pi^2m(U_b-E)}{h^2}}...

Can the phenomenon of quantum tunneling be explained? Any theory that can account for it? Or is it just empirical? Would someone kindly answer my questions? o:)

in barrier tunneling, if voltage is applied between two different materials, for eg Cu and Al and then the polarity is inversed, will there be any difference in the tunneling current?

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...

If two capacitor plates at a moderate voltage (200-300V) and low capacitance are kept very close to each other would there exist a tunneling current between them. If the tunneling current will exist, then it will gradually reduce the energy of the capacitor. Where will the used capacitor...

I have some questions about barrier tunneling in a scanning tunneling microscope. From what I know, the microscope consists of a one atom tip very close to the surface of the metal being examined. A potential difference is applied between the tip and the metal and some of the electrons manage...

Im learning about quantum tunneling and read something about that there are classical solutions at imaginary times, so called instantons? Can anyone help me out with this connection?

the causality problem and tunneling?

Consider a Quantum Mechanical particle approaching a barrier (potential) of height V_0 and width a. What will the sketch of the probability density look like if there is a 50% chance of reflection and a 50% chance of transmission? Can you explain why cause after reading Griffith' s Quantum...

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...

Hi! I always thought that tunneling was a quantum phenomenum. So another day I found a problem which is about the part of the light that can be transmitted (refracted) even if you send I light beam in an angle greater then the limit angle of two material boundary. By the way looking at a...

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

When a beam of electrons (near relativistic or non-rel.) intersects with a beam of protons or a "fixed" proton target, what percentage of the electrons tunnel through the proton(s) or is there an absence of electrons on the exact opposite side (the backside) of the proton? This question is a...

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...

Do neutrinos experience tunneling, and thus we think they have no mass yet they do because they are tunneling? Pete

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 an ensemble of quantum partcles, with energy E, traveling in x direction encounter a very wide potential barrier V0 > E, the ensemble wavefunction will exponentially decay within the barrier. I thought that meant that there was a small probability of detecting an electron within the...

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?