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Square well/barrier 
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#1
Apr511, 05:20 PM

P: 339

Square potentials (finite or infinte, well or barrier) are used in intro Quantum Mechanics courses. My question is:
What does the word 'square' signify? 


#2
Apr511, 05:28 PM

P: 339

My other question:
In the infinite square potential well model, the wavefunction outside the well is zero. Two reasons are usually put forward: 1. V is infinite. So Vu is infinite unless u = 0. (I don't understand what's still wrong with Vu being infinite.) 2. The particle can't be in a region of infinite potential if it lacks infinite energy. (Why not? Why should classical principles dictate quantum rules? Moreover, in the finite square well model, there is a finite probability of the particle being within the potential barrier? Isn't that a violation of the classical principle we are using in the above argument?) Therefore, u = 0. Thanks for any help. 


#3
Apr511, 05:42 PM

P: 789

Square refers to the appearance of the plot of V versus x.



#4
Apr511, 07:18 PM

P: 339

Square well/barrier
How can the other term represent the kinetic energy? How can positive and negative infinity add to give a finite positive number? What does 'steady state mean'? Thanks for all the help! 


#5
Apr611, 12:12 PM

Sci Advisor
P: 1,866




#6
Apr611, 01:04 PM

P: 846




#7
Apr611, 03:11 PM

P: 789

Thanks for all the help![/QUOTE] 


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