Register to reply 
Square well/barrier 
Share this thread: 
#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: 865




#7
Apr611, 03:11 PM

P: 789

Thanks for all the help![/QUOTE] 


Register to reply 
Related Discussions  
Quantum Tunneling Across a Square Barrier  Advanced Physics Homework  2  
Finite Square Barrier  Quantum Physics  5  
Quantum  Square barrier (help!)  Advanced Physics Homework  3  
What exactly is barrier tunneling and potential barrier?  Quantum Physics  6  
Finite Square Well/ Barrier  Advanced Physics Homework  2 