Quantum tunneling Definition and 131 Threads

Wikipedia states that, after he heat death of the universe: "Random quantum fluctuations or quantum tunneling can produce another Big Bang in years." How would this work?

Homework Statement The electron enters a straight pipe of circular cross section (radius r). The tube is bent at a radius R≫r by the angle α and then is aligned back again. Find the probability that the electron will jump out Homework Equations Tunneling probability in WKB approximation. The...

I have done my research and understand why quantum tunneling happens and I fully understand that there is no point at which the particle examined ever actually intersects with the barrier. The only part at which my knowledge feels fuzzy is at the mathematic equations. If a large object, such as...

I have question that involves quantum tunneling and wave function collapse that occurs when the state of an object is measured. I will try to explain what I mean. We don't know the exact location of an electron in an atom, because it doesn't have a location, it is in its wave form and we can't...

Homework Statement What is the approximate transmission probability (in %) of an electron with total energy 1.524 eV through a barrier of thickness 343 pm, and a potential height of 2.654 eV? (Does it matter what the potential energy is before and after the barrier? Not really, as long as it is...

General Relativity allows a potentially infinite number of spacetimes that are inaccessible to each other (except perhaps at the event--presumably lacking either duration or extent because of its instantaneity-- of their formation), as far as I can recollect from my sketchy reading of Sklar's...

As simply as possible, could someone try to explain how one would go about calculating the probability of a electron/(electric voltage) quantum tunneling through an insulator (preferably using an example please)? And how small would the insulator, and how large would the current/voltage have to...

Hi pf, I'm fairly new to QM so this may seem like a trivial question. As I understand it, an electron (or any small particle) does not have a definitive position in space until it is observed which causes the quantum wave like nature of the particle to disappear (collapse of the wave function)...

Is it possible to build a fast, accurate scale using QTC? If so, could someone explain the basics or point me toward a good resource? Thanks!

Hi Let's say I am supposed to animate the movement of some one-dimensional wavefunction as it hits a finite potential barrier like this: I was supposed to know how to do this over a year ago, but I am never certain how to write the algorithm. What confuses me the most is how to show the...

Just watched Intersteller and my mind started running wild with all sort of fun thoughts. So I'm not sure how serious of a questions this is, but I got to thinking if it's possible to use gravity waves as a form of communication. And in turn, started wondering how said waves could be detected...

I thought I would ask this question in the quantum mechanics section as I presume it has something to do with QM, like the reason why alpha and beta decay do not happen immediately but instead there is a half life for this decay. My understanding is that with alpha decay, the strong nuclear...

Could a photon utilize quantum tunneling to escape the threshold of a black hole or the confines of the curvature of space-time? Could any particle for that matter?

Is it possible to achieve teleportation of data or energy on long distances with help of quantum tunneling some day? Possibly it will require de Broglie wavelength manipulation? How de Broglie wavelength of an electron, for example, could be increased without cooling it to the one trillion's of...

Homework Statement Calculate the reflection probability for a 5 eV electron encountering a step in which the potential drops by 2 eV The Attempt at a Solution To answer this question, wouldn't I need to know where E > U or U > E? Also wouldn't I need to know the width of the...

Homework Statement A particle of energy E approaches a step barrier of height U. What should be the ratio E/U be so that the reflection coefficient is 1/2. Homework Equations Transmission + Reflection = 1 Transmission = e^(-2a*alpha) a = mw∏/h alpha^2 = (8m∏^2/h^2)(U-E) Reflection...

I know that the Sun radiates vast amounts of energy partly due to nuclear fusion. I've also heard that nuclear fusion can occur in the Sun due to quantum tunneling. I'd like to know how the process of quantum tunneling in the Sun allows nuclear fusion to take place. Thanks!

Hello everybody, I am a first year student and I have a question about tunneling. If we have an electron which is bound by an atom. And that electron has a high probability to tunnel through the barrier that keeps it confined. So it manages to 'escape' from the atom. Shouldn't its energy...

Hello everybody, I am a first year physics student and I have a question about the probability for 'heavy' nucleus to decay. I was thinking the other day, how can we know the probability for that nucleus to decay. Let's suppose that we have an alpha decay. Is the probability of the nucleus...

Hello fellow scientists, Do all stars rely on quantum tunneling for fusion or do high mass stars break the Coulomb barrier without tunneling? Thanks

Hi everyone Homework Statement I have to calculate the probablity that someone can tunnel a wall with a car. I have the mass of the car and the velocity and I know that the wall is 20 cm wide. But I have troubles estimating the potential of the wall. Homework Equations - The...

If an election can tunnel through atomic structures, or move through atomic barriers even when they don't have enough energy, could it be possible to create fusion through tunneling, even without sufficient energy, sufficient relative to standard energy levels needed? I am thinking that it...

Hi, My friends! According to quantum mechanics books ,a particle has some probability hop through the potential even when the potential is large than kinetic energy. They all explain the phenomenon by solving Schrodinger equation. Indeed, the wavefunction doesn't equal 0 behind the potential...

Hi, I am a physics student but still a layman in QM. I got a task to explain Quantum tunneling and I did my researchs for 3 days (I have read almost all threads here regarding to the topic). I found many different interpretations but I believe the Schrodinger's Equation is the correct answer...

It involves quantum tunneling, both of us know very little about physics but I watched a video on youtube about a guy explaining quantum tunneling, from what I underdstand a particle can, with enough energy pass right through other solid surfaces? So I said that if you had a penny, and shot it...

Would a water wave leak just like an electron with a barrier?

Alexander Vilenkin has a model of cosmic origins which describes the universe coming into being as a quantum tunneling event. The problem that I see with this, is that this requires the universe to be closed. However, we know the universe is probably flat with a margin of error of less than 1%...

Homework Statement I am given a metal-oxide-semiconductor device. I apply a positive voltage (30 V) on to the metal. Theoretically, the electrons should tunnel through the oxide. I want to calculate the oxide thickness for only 5% of electrons tunneling through the oxide. Homework Equations...

A quantum particle can tunnel through a barrier and we can describe why this is so by the uncertainty principle. However, there is something I want to clarify about the reasoning behind this. I believe the argument goes like this: Imagine the quantum particle never entered the barrier and we...

Hello. Okay, so there are some theories like string theory that say that there are extra dimensions of space that we cannot see. Extra dimensions if they exist would allow more degrees of freedom in movement. This website demonstrate how barriers insurmountable in a lower dimension would be...

We have some material with metal atoms inserted in substrate.Maybe by dopping. Electric current is able to move only be quantum tunneling jumping from atom to atom. Could we obtain superconductor in this way?

Homework Statement The edge of a nucleus can be roughly modeled as a square potential barrier. An alpha particle in an unstable nucleus can be modeled as a particle with a specific energy, bouncing back and forth between these square potential barrier. Consider a nucleus of radius r and an...

It's on page 4 (this isn't homework, just something I stumbled upon, it's also in Griffith's 8.17):http://www.physics.udel.edu/~msafrono/425/Lecture%2018.pdf . Can someone help me understand this solution? What exactly is happening...are there particles at h/2 that are smashing against the...

Imagine we have material with very low heat conductivity in which metal nanoparticles are embedded and distance between each those nanoparticles is 1 nm.When we heat one side of such material,will electrons tunnel to the colder side?Is it possible some usefull energy generate in this way?

You know how every particle has a non zero probability of being anywhere, but what about outside the particles Hubble sphere? In other words, does is there exist a nonzero probability that a particle can travel at superluminal speeds across the universe?

I was reading "The physics of superheroes", and it mentioned The Flash being able to increase his kinetic energy to tunnel though walls. I tried to find out how fast he would have to go, assuming he is vibrating (as shown in the actual comic) so will have several tries at trying to tunnel though...

Homework Statement Two copper conducting wires are separated by an insulating oxide layer. This layer acts as a square barrier of height 10 eV. Estimate the transmission coefficient for penetration by 7 eV electrons (a) if the layer thickness if 5 nm and (b) if the layer thickness is 1 nm...

Taken from an entirely empirical standpoint, the true nature of Consciousness should be the Chinese room argument, that it is nothing but an illusion created by the interactions of billions of neurons, electrical and chemical signals. Supposedly this would disprove "The Human Soul" and...

Hey there, I'm pursuing a degree in Msc. Nanoscale science, and I've been studying about Scanning tunneling microsopes that use Quantum tunneling to study the surface struture of materials. My question is: What is the maximum distance between the surface that's been studied, and the STM tip...

Alright, so there's definitely a lot of Sci-Fi hype about Entanglement. I'm sort of hoping the experts on the subject can set this straight. Question: Could it actually be used to transfer information instantly from one point to another, seemingly providing FTL communication? And second, does...

How close do two room temperature deuterium nuclei need to be to each other to have a one-in-a-quintillion chance of "tunneling" into each other so that the nuclear forces bind them together despite the repulsive effect of the positively-charged protons?

I've heard that Sun is not hot enough to sustain thermonuclear fusion at the level we observe. Instead, the solar output relies on quantum tunneling of protons through their natural repulsive barrier. Might this same effect be useful in obtaining controlled thermonuclear fusion? It seems to me...

So I've been reading up on some quantum tunneling. It seems as though everything I read on it only conveys an elementary view on the matter, as if their target audience was the general public. I am here to gain a more sophisticated understanding of this concept. As I currently understand...

Howdy, Can anyone explain qualitatively (without using any maths) why a particle with a smaller mass has a greater probability of tunneling through a potential barrier than another particle with a larger mass but of the same total energy? Thanks

Is it possible to achieve commercially viable nuclear fusion in purely electrostatic quantum tunneling way?What should be voltage of electrostatic field (no particles bombarment) to overcome Coloumb bareer and make tunneling fusion probable?

It is a theory, but quantum computing could most likely out perform classical computers. In this regard, would it limit the progression of AI if it could go beyond classical computing? Assuming that quantum computing catches up and out performs classical computers, will computer engineers have...

Good day, everyone! Lately I faced the necessity of solving a problem from a field I know literally nothing about. So I just made an online research but without success. Any help (hints, good sources, relevant equations) would be greatly appreciated! Homework Statement Gold nucleus (Au...

Hey everyone, For my a research project on quantum tunneling I have to tie in math somehow, so I was wondering if anyone could help me learn to calculate the probability of a wave (preferably like an electron or electrical voltage) of some sort passing through a rectangular barrier, which is...

Hi, I'm doing a research project for my high school physics class. I originally set out to research touch screens but was disappointed with how simple the mechanics of the iphone are (or at least the basic physics of it). I continued researching and found that soon Quantum Tunneling may be...

I'm trying to find the experimental evidence for quantum tunneling during a fusion reaction. Take the simple D + D -> T + P reaction. I know that the energies required to make this happen are much lower in actual experiment than what would be predicted by Coulomb's model of the electrical...