Recent content by Jaime_mc2

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    I Dimensions of quantum cell automata's state space

    In the paper C. S. Lent and P. D. Tougaw, "A device architecture for computing with quantum dots," in Proceedings of the IEEE, vol. 85, no. 4, pp. 541-557, April 1997, doi: 10.1109/5.573 about quantum dots, it is stated that the basis vectors in the space of quantum states for a single cell...
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    I Integral-form change of variable in differential equation

    I have the following differential equation, which is the general Sturm-Liouville problem, $$ \dfrac{d}{dx} \left[ p(x) \dfrac{d\varphi}{dx} \right] + \left[ \lambda w(x) - q(x) \right] \varphi(x) = 0\ , $$ and I want to perform the change of variable $$ x \rightarrow y = \int_a^x \sqrt{\lambda...
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    I Energy in the Hamiltonian formalism from phase space evolution

    The hamiltonian ´for a free falling body is $$H = \dfrac{p^2}{2m} + mgy$$ and since we are using cartesian coordinates that do not depend on time and the potential only depends on the position, we know that ##H=E##. For this hamiltonian, using the Hamilton's equations and initial conditions...
  4. J

    I Normal modes of vibration from the total energy

    A mass ##m## is restricted to move in the parabola ##y=ax^2##, with ##a>0##. Another mass ##M## is hanging from this first mass using a spring with constant ##k## and natural lenghth ##l_0##. The spring is restricted to be in vertical position always. The coordinates for the system are ##x##...
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    I Changing spherical coordinates in a Lagrangian

    In order to compute de lagrangian in spherical coordinates, one usually writes the following expression for the kinetic energy: $$T = \dfrac{1}{2} m ( \dot{r}^2 + r^2 \dot{\theta}^2 + r^2 \sin^2 \theta \dot{\phi}^2 )\ ,$$ where ##\theta## is the colatitud or polar angle and ##\phi## is the...
  6. J

    Solve a nonlinear equation using fixed-point iteration in MATLAB

    You are plotting just one point at the end, with coordinates (maxiter + 1, x(maxiter + 1)). If you want to plot ##g(x)##, you should do something like this (for example before calculating the fixed-point): x= -10:0.01:10; g = x^5-3*x^3-2*x^2+2; plot(x, g); After this, you should calculate the...
  7. J

    Show that the Hamiltonian operator is Hermitian

    I would better say that, if ##f## and ##g## are valid wavefunctions, then both belong to the complex space ##L_2(\mathbb{R})##, which is a Hilbert space if we consider the scalar product defined as $$ \langle f | g \rangle = \int_{-\infty}^{\infty} f^*(x)g(x)\ dx\ . $$ By definition, the...
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    B How do quantum computers find a solution?

    I think those are interesting questions and I will try to answer it briefly but with enough explanations. Also, consider that I'm not an expert in this area, so I may be wrong in some details, although I have been studying quantum computing seriously for some time for my master thesis, so I...
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