Notices
 

[MCQ/QM-13001] energy eigenfucntion of 2 dim oscillator

For page specific messages
For page author info

A particle of mass \(m\) in potential
\(V(x,y)=\frac{1}{2}m\omega^2(4x^2 + y^2)\) is in the energy eigen-state
with \(E=\frac{5}{2}\hbar \omega\), then is eigenfunction will be 

  1. \(y \exp\Big(-\frac{m\omega}{2\hbar}(2x^2+y^2)\Big)\)
  2. \(x \exp\Big(-\frac{m\omega}{2\hbar}(2x^2+y^2)\Big)\)
  3. \(y \exp\Big(-\frac{m\omega}{2\hbar}(x^2+y^2)\Big)\)
  4. \(xy \exp\Big(-\frac{m\omega}{2\hbar}(x^2+y^2)\Big)\)

 

RECALL IMPORTANT FACTS

For a harmonic oscilaltor in one dimension

\( H = \frac{p^2}{2m} + V(x,y) = \frac{p^2}{2m} + \frac{1}{2} m \omega^2  x^2\)

\(E =(n+1/2) \hbar \omega\)

\( u_n(x) = H_n(x) \exp\Big(\frac{m\omega}{2\hbar} x^2\Big)

NOTE IMPORTANT POINTS

  • Two dimensional oscillator
  • Frequencies \(\omega_1=2\omega, \qquad \omega_2=\omega\),
  • Total energy  \(E=(n_1+1/2) \hbar \omega_1 + (n_2+1/2)\hbar \omega2 = \hbar\omega(2n_1+n_2 +3/2)\)Therefore (2n_1+n2)=1 This has only one solution in integers \(n_1=0, n_2=1\)
  • Hermite polynomial \(H_1(y)\) will  give \(y\) factor no \(x\) factor for \(H_0(x)\) ,So choice is between Option 1 and Option3.
  • The  \(x\) part of the exponential factor is correct in Option (a) because we need  \((m\omega_1 /2\hbar) x^2\).

ANSWER

Option (a)

 

Exclude node summary : 

n
0
 
X