User:EditingPencil/sandbox/Misc

Quantum Harmonic Oscillator

It follows from momentum space definition of position operator as x = i\hbar\frac{\partial }{\partial p}, that by using Schrodinger's equation and taking m_0=\frac 1 {m\omega^2} , we get:

\begin{align}

\frac 1 {2m} p^2 \psi(p) -\frac 1 2 m \omega^2 \hbar^2\frac{\partial^2 }{\partial p^2}\psi(p) = E \psi(p)\\

\frac 1 2 \frac{1}{m_0} (-i\hbar \nabla_p)^2\psi(p)+\frac 1 2 m_0 \omega^2 p^2 \psi(p)=E\psi(p)

\end{align}

Since momentum basis Schrodinger equation is same as that of position basis Schrodinger equation, the real-valued momentum wavefunction solution is same as momentum wavefunction corresponding to spatial wavefunction up-to an arbitrary phase which can be found to be (-i)^n for E_n energy eigenfunction. Hence the change x \rightarrow p, m\rightarrow\frac 1 {m\omega^2}, \omega \rightarrow \omega and |n\rangle \rightarrow (-i)^n|n\rangle in any equation expressed in terms of those variables gives another valid equation.

Configuration space

Finding x(t) from given v(x) curve in configuration space, x\left(t=t_0+\int_{x=x_0}^x \frac {dx}{v(x)}\right)=x.