Register to reply 
Compatibility of qunatum measurements 
Share this thread: 
#1
Dec1605, 05:41 PM

P: 76

The question is "two operators A,B do not commute". Is it true that
([A,B]psi) does not equal zero for any state psi?" I'm not sure if there are any cases in which a state psi could produce this result (except for the obvious one where psi = 0 and there is no particle). Thanks 


#2
Dec1605, 06:20 PM

Sci Advisor
HW Helper
P: 1,332

Here is a hint: think about the commutator [tex] [x^2 , p] [/tex]. Can you find a state that gives zero when you hit it with the commutator even though commutator isn't identically zero?



#3
Dec1705, 04:39 PM

P: 76

I've tried applying the commutator to an arbitrary psi and i get i*h bar * 2x* psi. The only case where I can think of this equalling zero is when psi = 0, which is the obvious case of having no particle.



Register to reply 
Related Discussions  
Compatibility, H2 embrittlement  Materials & Chemical Engineering  0  
Qunatum Angular Momentum  Advanced Physics Homework  6  
Qunatum Mechanics Help me !..  Academic Guidance  3  
Could you make two brains  Medical Sciences  31  
Electromagnetic compatibility  Electrical Engineering  0 