Fermi Question - quantum tunnelling of a person

PsiPhi
Messages
19
Reaction score
0

Homework Statement



The probability of a person quantum mechanically tunnelling through a wall

Homework Equations



The Attempt at a Solution



I'm not too sure how to approach this problem, I calculated the de Broglie wavelength of the person (mass = 60kg, velocity = 30 m/s; These values are made up by me). But then I get stuck, what can I infer from the wavelength that is calculated. I looked at the barrier potential problem, and I'm not sure how to construct a wavefunction for the person (if it is even possible? I thought of using the plane wave solution and calculating the momentum and wavenumber that appears in the complex exponential term), also the wall would represent the barrier potential (would this potential tend to infinity? like the infinite square well problem?)

My brain is melting...
 
Physics news on Phys.org
I guess that you have to estimate the probability for EACH single atom to tunnel through the potential barrier and then multiply all the probabilities together and get something like almost 0. However, I don't know how to calculate the energy for each atom and how many atoms our body has.
 
Sounds reasonably straightforward to use a plane wave type tunneling problem as a model. But I have no clue how you are supposed to estimate the height of the potential barrier. If it's infinity, there is no tunneling.
 
I know this is cheating but I found the answer here http://physuna.phs.uc.edu/suranyi/Modern_physics/Lecture_Notes/modern_physics6.html
 
Last edited by a moderator:
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top