Schrödinger Definition and 611 Threads

  1. M

    Schrodinger Equation and seperation of variables

    Hi, In Griffiths QM, it is claimed that to solve the Schrodinger Equation, we take the solution wavefunction \Psi(x,t) to be of a seperable form \psi(x)\phi(t). He then says that a superposition of these seperable forms can always give us the general solution. Can someone help me prove that...
  2. L

    Understanding schrodinger equation

    Note : I am not sure this is the right section for posting it , but from the rules section i saw that this section can be used for homework related queries and independent study . Homework Statement Understanding schrodinger equation . i want to understand the solutions of this equation and...
  3. Y

    Schrodinger Equation in a representation

    The general evolution of a ket |\psi\rangle is according to -i\hbar\frac{d}{dt}|\psi\rangle=H|\psi\rangle without specifying a representation. From this equation, how can you simply get a equation in a certain representation F as below: -i\hbar\frac{\partial}{\partial t}\langle...
  4. N

    The Schrödinger equation as the non-relativistic limit of the Dirac equation

    Hello, I'm reading Griffiths' introduction to elementary particles and he seems to claim that the Schrödinger equation can be seen as a non-relativistic limit of the Dirac equation. I was wondering how one could deduce this, e.g. how do we go from \mathcal L = \bar{\psi} \left( i \gamma^\mu...
  5. 3

    Question about Schrodinger equation

    Ok, I understand the schrodinger equation for the most part, the thing is though, I don't understand what ∂ means... In the equation:(∂^2ψ/∂x^2)+8(pi)m/h^2(E-V)ψ=0 It pops up two times. The rest of the equation is kinda self explanatory, but I don't know what on Earth ∂ means please, tell me...
  6. F

    Comparing Dirac and Schrodinger Equations for the Hydrogen Atom

    The Schrodinger equation solved for the hydrogen atom gave good agreement with spectral lines, except for line doublets. To account for these electron spin theory was grafted onto the theory, despite the problem of electron being a point particle. In 1928 Dirac gives his different answer...
  7. G

    Separation of Variables in Spherical Schrodinger Equation

    The normalization condition is: ∫|ψ|^{2}d^{3}r=1 In spherical coordinates: d^{3}r=r^{2}sinθdrdθd\phi Separating variables: ∫|ψ|^{2}r^{2}sinθdrdθd\phi=∫|R|^{2}r^{2}dr∫|Y|^{2}sinθdθd\phi=1 The next step is the part I don't understand. It says: ∫^{∞}_{0}|R|^{2}r^{2}dr=1 and...
  8. C

    Solving Schrodinger DE using Frobenius

    My DE is \frac{h^2}{2m} \frac{d^2\psi}{dx^2} + \left(E - \frac{Ae^{-ax}}{x} \right) \psi = 0 where h, m, A < 0 and a and E are constants. I need to construct the following series solution (using the larger root of my indicial equation): \psi(x) = a_0 \left[x + \frac{Am}{h^2}x^2 +...
  9. S

    Schrodinger Equation in 3 dimension

    How can i solve Schrodinger equation in 3dimension i want to know how can i deduce every equation ? and how can i find equation of spherical harmonic and radial equation ? i need to understand this proof
  10. S

    Understanding the Schrodinger Equation and 1/2 Spin in Quantum Mechanics

    Hi all, In class I've recently been taught the schrodinger equation and about spin(couple weeks apart). My questions are- 1. In laymans terms, what exactly does the S-eqn mean? What I have taken it to be so far, is an equation that determines the probability of the position of an e- in...
  11. D

    Lagrangian Density, Non Linear Schrodinger eq

    Homework Statement Derive the Non-Linear Schrödinger from calculus of variationsHomework Equations Lagrangian Density \mathcal{L} = \text{Im}(u^*\partial_t u)+|\partial_x u|^2 -1/2|u|^4 The functional to be extreme: J = \int\limits_{t_1}^{t_2}\int\limits_{-\infty}^{\infty}\...
  12. H

    Imaginary numbers and the real part of the Schrodinger Equation

    At the moment I am studying the Schrodinger equation using this resource. In a 1D solution (sec 3.1 in the paper) they show that a wave function can be expressed as \Psi(x,t)=\sqrt{2}e^{-iE_{n_x}t}\sin (n_x\pi x) where n_x is the quantum number. And they show the real part of the solution in...
  13. S

    Schrodinger and Infinite Square Well hell

    Schrodinger and Infinite Square Well... hell Homework Statement Show that Schrodinger Equation: \frac{d^{2}\psi(x)}{dx^{2}}+k^{2}\psi(x)=0 has the solution \psi(x)=A\sin(kx) Homework Equations k=\frac{\sqrt{2mE_{tot}-E_{pot}}}{\hbar} The Attempt at a Solution I already know that...
  14. T

    Why i in Schrodinger Equation

    Why "i" in Schrodinger Equation Schrodinger Equation is "i*h*dphi/dt=H*phi" That is to say that the change in the state is proportional to a linear tranformation of the actual state (I understood the logic behind that), H is hermitian and that means that its eingenvalues are real (right?)...
  15. G

    Solving the Schrodinger Eqn for 1-D Atom

    Homework Statement By substituting the wave function \psi (x) = Ax{e^{ - bx}} into the Schoedinger equation for a 1-D atom, show that a solution can be obtained for b = 1/{a_0}, where {a_0} is the Bohr radius. Homework Equations - \frac{{{\hbar ^2}}}{{2m}}\frac{{{d^2}\psi...
  16. C

    Solving a time independent Schrodinger equation

    Homework Statement Hello! I am currently stuck with a time independent Schrodinger equation where the potential "V(x)" is hyperbolic in nature. I was wondering if anyone could give me a hint as to how I should approach this problem in order to get an analytical solution (without using...
  17. M

    The radial schrodinger equation

    Hi, I'm doing a homework problem in my modern physics class and I'm stuck at a point. The question is "Show that the radial probability density of the 1s level in hydrogen has its maximum value at r = a0, where a0 is the Bohr radius" I know that the radial schrodinger equation will...
  18. A

    Does schrodinger equation give complete description of electron?

    is schrodinger equation capable of explaining all the properties of electron dynamics or are there any anomaly..? THANKS IN ADVANCE
  19. R

    Schrodinger equation of particle in box

    hi all please help me... I'm learning schrodinger equation of a particle in a 1-dimensional box. I read a quantum mechanics book written by A. C Phillips. the wavefuction is ψ (x,t)= N sin (kx) e-iEt/hbar but when I compared to what I read from a modern physics book written by Beisser. the...
  20. S

    Schrodinger equation for one dimensional square well

    Homework Statement the question as well as the hint is shown in the 3 attachments Homework Equations The Attempt at a Solution i know how to normalize an equation, however i do not understand what the hint is saying, or how to do these integrals, any guidance would be greatly...
  21. C

    How Does a Proton's Wave Function Behave at a Potential Barrier?

    Homework Statement Proton traveling along the x-axis approaches a potential barrier at x = 0 Height of potential barrier - U0 = 20eV Proton Velocity = 44km/s = 44,000m/s Asked to show that the solution to the one dimensional time independent Schrödinger equation is \psi(x) = A sin...
  22. S

    Schrodinger equation, normalizing

    Homework Statement Consider the infinite well, a particle with mass m in the potential V(x) = \begin{cases} 0, & 0 < x < a,\\ \infty, & \text{otherwise,} \end{cases}, At t = 0 the particle is in the state: \Psi(x,0) = B \left[\sin{\left(\frac{l \pi}{a}x\right)} +...
  23. S

    Solving schrodinger, reflection coefficient

    Consider the potential V(x) = \begin{cases} 0, & x < -a & (I) \\ +W, & -a < x < a & (II) \\ 0, & x > a & (III) \end{cases} for a particle coming in from the left (-\infty) with energy E (0 < E < W). Give the solution to the Schrodinger equation for I, II and III and use these to...
  24. N

    Looking for: Schrödinger equation in terms of phase and modulus

    Hello, I can't seem to find a reference formulating the Schrödinger equation as a set of two differential equations in terms of the modulus |\psi| and the phase S instead as one diff. eq. in terms of the complex wavefunction \psi = |\psi|e^{i S}. Can anyone show me the way?
  25. T

    Solving the Schrodinger Equation for A and l

    I have the following Schrodinger equation: i* (h-bar) * partial derivative of ψ(x,t) w.r.t time = [(m*w^2 / 2) * x^2 * ψ(x,t) ] - (1/2m) * (h-bar)^2 * (laplacian of ψ(x,t))] m>0 is the mass w is a positive constant Assume that the ground state...
  26. H

    Why isn’t time-dependent Schrodinger equation separable?

    Greetings everyone, I haven’t done any quantum in a while, and was reviewing my textbook, Griffiths Ed. 1. The form of the Schrodinger equation I’m using is: i\hbar\partial\Psi/\partialt = -\hbar2/2m * \partial2\Psi/\partialx2 + V\Psi The book says if V is a function of x only, then the...
  27. C

    Schrodinger Equation and wavefunctions

    not all functions are wavefunctions. For functions to be wavefunctions they have to obey a series of "rules". Now, my question is: there are many functions, which obey these rules which aren't eigenfunctions of the hamiltonian, thereby meaning that they don't obey the Schrodinger Equation...
  28. A

    Applying the FTC to an arbitrary solution of the Schrodinger equation

    Suppose you've got a function \psi(t) that satisfies i\dot \psi = H \psi for some self-adjoint Hamiltonian H. I'd like to apply the fundamental theorem of calculus to this guy and write something like \psi(t) - \psi(0) = \int_0^t \psi'(s)ds. Can I do this, given only the very bare...
  29. T

    Solving the Schrodinger Equation: WHAT DOES IT ALL MEAN?

    I'm an A-level student (I don't know what the US equivalent is sorry, I'm not an undergraduate is what I'm saying), and I've independently done a project on wave functions for a few simple stationary systems; particle in a box and quantum harmonic oscillator are the ones I focused on in the end...
  30. T

    Bra-ket notation Schrodinger Equation

    This is a pretty trivial question, but how is the Schrodinger equation written out in full, time dependency and all in Dirac notation? I'm interested in this from a purely aesthetic point of view but I'm also a bit confused as to what the bras and the kets really are.
  31. W

    Understanding Wave Function and Schrodinger Wave Equation

    hi , can anyone please explain to me what is wavefunction - and can we apply schordinger wsve equation to simple pendulum. thanks
  32. D

    3D Schrodinger Equation of a Wire for Energy Levels - Quantum Physics

    Homework Statement Given a wire with length a and square base b x b (where a >> b), show that the first 1700 (approximately) levels of the electron in the wire are identical for the one dimensional box, when a = 1m and b = 1mm. Homework Equations I know that the allowed energies of...
  33. A

    Schrodinger Quantization VS Bohr Quantization

    Homework Statement What are the similarities and differences between the quantization of angular momentum in the Schrodinger theory and in the Bohr model? Homework Equations ? The Attempt at a Solution Similarities: -In both theories, the principal quantum #, n, determines the...
  34. B

    Quantum Mechanics, Schrodinger equations and energy eigenvalues

    How do you find an expression for the energy eigenvalues from the TISE (Time Indipendant Schrodinger Equation) for a given potential. e.g. why is: E = (N + 1) hbar*omega an expression for the energy eigenvalues for a potential of: V = 1/2*m*omega2x2 ?? I really have no idea where to start...
  35. U

    Solution of Schrodinger equation for free electron

    Hi, i am beginning elementary Quantum Mechanics as my course. While studying one question arise in my mind : In the solution of Schrodinger wave equation there are two parts. ψ=A*exp(jKx) + B*exp(-jkx). (for confined electron) But when dealing with free electron the solution is of...
  36. G

    Schrodinger equation normalization to find A -Griffiths

    Homework Statement In David Griffiths Introduction to Quantum Mechanics (2nd ed.), page 32 he normalizes a time independent wave function to get the coefficient A. He dropped the sine part of the integration with no explanation. What is the justification. Homework Equations The time...
  37. M

    Show that this function satisfies Schrödinger equation for hydogen?

    Homework Statement Show that function Y = C sin θ (5cos2θ - 1 )ei\phi satisfies Scrhödinger equation for hydrogen? Homework Equations The Attempt at a Solution I derivated the required elements of the equation but ended up to some messy equation with lots of sines and...
  38. R

    Time dependant Schrodinger Equation Leapfrog Method

    Hi, I'm trying to set up a programme to compute the numerical solution to the time dependant schrodinger equation of a ground state wave packet in a harmonic oscillator using the leapfrog method. I've been at it for two weeks trying different methods and I'm starting to get extremely stressed...
  39. X

    Schrödinger equation in momentum space and number of solutions

    Hi, Note: I will be sloppy with constant factors in this post. Only the general structure of the equations matters. Consider a particle in a linear potential, \frac{\mathrm d^2}{\mathrm d x^2} \psi(x) + x \psi(x) - E \psi(x) = 0. Mathematically, this is a second-order ODE, and there...
  40. I

    I need just ONE analytic solution to the time-dependent Schrodinger Equation.

    I have been trying to find an analytic solution to the time-dependent Schrodinger Equation. I plan to make a movie of the probability function as it changes over time, but I can't seem to find any analytic solution for the wave function. Is it possible to solve the time-dependent Schrodinger...
  41. A

    Solving Schrodinger Eq.: Quantum #s for n=0,1,2

    Homework Statement The solution of the Schrodinger equation for atom depends on four quantum numbers: the principal n, the orbital l, magnetic m1, and the spin Ms n = 1, 2, 3, 4, ... (integers) l = 0, 1, 2, ... (n-1) m1 = -1, -1+1,...0...1-1, 1 Ms = -1/2, 1/2 List all possible values of...
  42. S

    Newbie Schrodinger equation question

    I discovered physics at a later age and am trying to learn more about Schrodinger's equation, here it is in one dimension -- got to crawl before you walk, I guess -- http://scienceworld.wolfram.com/physics/SchroedingerEquation.html == my question is the variable that is multiplied by i x h bar...
  43. G

    Schrödinger equation for particle on a ring in a magnetic field

    hi i need the schrödinger equation for a particle(electron) in a ring under the influence of a magnetic field that goes through perpendicular to the plane of the ring and i want to consider the spin too. Well, the particle in the ring is pretty easy: - \frac{ \hbar^2}{2mr^2}...
  44. andrewkirk

    Why doesn't wave function collapse contradict Schrodinger equation?

    The postulates of quantum mechanics include: (1) Schrodinger's equation describes how the wave function of a system changes over time, and appears to make the wave function continuous over time. (2) When a measurement is made of quantity m, the wave function instantly changes to an...
  45. S

    Solving 2-D Schrodinger Equation?

    Homework Statement A particle of mass m is confined in a two-dimensions by the potential energy V = 1/2k(x2+4y2). Write down the Schrodinger equation for the system. Write down the ground state wave function and find the lowest four energy levels in terms of the quantities ħ, k, m etc. Make...
  46. L

    Schrodinger Equation: No Higher Powers of ψ

    ψ and its derivatives occur only linearly in the Schrodinger equation, that is, second or higher powers of these quantities do not appear in the equation. Schrodinger equation for a free particle is i\hbar∂ψ(x,t)/∂t = (-\hbar2/2m)(∂2ψ(x,t)/∂x2) Here (∂2ψ(x,t)/∂x2) is second power of ψ. Then...
  47. C

    Schrodinger equation for potential drop

    Homework Statement Hello! I'm looking at a situation where there is a finite potential Vo for x<0, but zero potential for x>0. For a particle moving from left to right, I'm wondering what coefficients for the solution to the Schrodinger equation are equal to zero, and also how to prove that...
  48. C

    Hamilton-Jacobi Equation related to Schrodinger?

    Hamilton-Jacobi Equation related to Schrodinger?? Where it comes from the Schrodinger equation? Is it related to Hamilton-Jacobi equation? And any good text to consult??
  49. J

    Schrodinger Equation: Particle in a Box

    Homework Statement We have been examining a one-dimensional infinite square well where the infinite walls are located at -b and +b. The energy levels in this quantum system are non-degenerate, that is for each energy there is only one wave function. Let us place an infinite potential step...
  50. G

    Energy from schrödinger equation

    hi i was currently thinking about this step here: \langle \psi_n, - \Delta \psi_n \rangle = \int |\nabla \psi_n|^2 dx how do you get from the laplacian to this other expression?
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