Recent content by Ziggy12

  1. Z

    Tip current in STM (fractional error problem)

    Yes sorry about that, it was a typo. Phi is the work function Well I looked it up and the work function does depend on voltage, so I guess I have to assume that \phi = (V-4)\hspace{0.1cm}\mathrm{Volts}, and not just 4 Volts as one could think from the problem.
  2. Z

    Tip current in STM (fractional error problem)

    Yes I could simply divide the current at two different distances to get \frac{i(s+\delta s)}{i(s)} = \frac{aVe^{-A\psi^{1/2}(s+\delta s)}}{aVe^{-A\psi^{1/2}s}} = e^{-A\psi^{1/2}\delta s} but then again, this is independent of the voltage V, so I don't see how I am supposed to solve the second...
  3. Z

    Tip current in STM (fractional error problem)

    Homework Statement Suppose the STM tip current is given by i = aV e^{-A\phi^{1/2}s} a) Derive an expression for the fractional change in tip current as function of fractional change in tip spacing s. b) If \phi = 4V select a reasonable set of V values so that a 1Å increase in s will cause...
  4. Z

    What Values of \( n \) Make the Given Lagrangian a Total Derivative?

    Homework Statement We have the Lagrangian $$L=\frac{1}{2}\dot q^2-\lambda q^n$$ Determine the values for n so that the Lagrangian transform into a total derivative $$\delta q = \epsilon (t\dot q - \frac{q}{2})$$ Homework Equations The theorem says that if the variation of action $$\delta S =...
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    3d harmonic oscillator, probability m=0

    Well I don't know those, that's the point. I don't know how $$n_x,n_y,n_z$$ relates to the quantum numbers $$n,m,l$$
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    3d harmonic oscillator, probability m=0

    If the magnetic quantum number m=0, then the obital quantum number l is also zero. This can only happens in the ground state. Correct me if I'm wrong. So basically it asks me what the probability of this state to spontaneously jump off from this state to the ground state? But if I know that the...
  7. Z

    3d harmonic oscillator, probability m=0

    Thanks for your answer. Yes sorry, it seems I forgot the y and z components. It supposed to be $$\psi_{1,0,0}(x,y,z)= \left(\frac{m\omega}{\pi \hbar}\right)^{3/4}\sqrt{\frac{2m\omega}{\hbar}}xe^{-\frac{m\omega}{2\hbar}(x^2+y^2+z^2)} $$ And the energy levels are...
  8. Z

    3d harmonic oscillator, probability m=0

    Homework Statement The problem asked me to derive an expression for the stationary wave function of the 3d harmonic oscillator which I have done. It then tells me a particle is in the stationary state $$\psi_{n_x,n_y,n_z}(x,y,z)=\psi_{100}(x,y,z)$$ and to express this in spherical coordinates...
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