Harmonic oscillator Definition and 743 Threads

  1. H

    7th grade Ground State Harmonic Oscillator problem

    Homework Statement Calculate the probability for finding the ground state harmonic oscillator beyond its classical turning points. Homework Equations Psi n(q) = (alpha/pi)^(1/4) exp(−alpha*q^(2)/2), where alpha = (kμ)^(1/2)/h bar The Attempt at a Solution i know it's going to be...
  2. C

    What Are the Two Possible Values of C in a Damped Harmonic Oscillator Equation?

    1. The equation of motion is Ma(t) +rv(t) + Kx(t)=0 a) Look for a solution of this equation with x(t) proportional exp(-Ct) and find two possible values of C. Homework Equations 3. No clue... Please help if you can!
  3. LydiaAC

    Is the Homogeneous Solution Neglected in Undamped Harmonic Oscillators?

    Hello friends: I do not understand why when solving the undamped harmonic oscillator equation dx/dt+w02x=Fcoswt I am allowed to neglect the homogeneous solution. I read that in a damped harmonic oscillator if you let the time pass, the homogeneous solution will disappear and you will...
  4. N

    Quantum harmonic oscillator problem

    Homework Statement Is there any way to find <\varphi_{n}(x)|x|\varphi_{m}(x)|> (where phi_n(x) , phi_m(x) are eigenfunction of harmonic oscillator) without doing integral ? Homework Equations perhaps orthonormality of hermite polynomials ...
  5. A

    Quantum Mechanics 1D Harmonic Oscillator Simulator

    Hi. I have recently designed a simulator about Qunatum Mechanics one dimensional harmonic oscillator. Please try it. I will be glad to read your opinions. http://erham.persiangig.ir/Programs/1386/QM1DHOS10.png Size: 223 KB http://erham.persiangig.ir/Programs/1386/QM1DHOS10.zip"
  6. S

    Perturbations and harmonic oscillator

    Homework Statement In a diatomic molecule with atom masses m1 and m2, the atoms are bound by a potential V(r)=V_0\big[ \big(\frac{r_0}r\big)^{12} - 2\big(\frac{r_0}r\big)^{6}\big] where r is the distance between the atom centra, r0 is the equilibrium istance, and V0 is a constant depending...
  7. N

    What Are the Correct Statements About a Quantum Harmonic Oscillator?

    Homework Statement For a 1D QM harmonic oscillator, (a) the discrete energy states are nhw (b) the discrete energy states are (n+0.5)hw (c) the lowest energy state wave function is ~\exp^\frac{-\alpha^2\ x^2}{2} (d) the probabilty of finding the particle outside the classical...
  8. N

    Perturbation of the simple harmonic oscillator

    [SOLVED] Perturbation of the simple harmonic oscillator Homework Statement An additional term V0e-ax2 is added to the potential of the simple harmonic oscillator (V and a are constants, V is small, a>0). Calculate the first-order correction of the ground state. How does the correction change...
  9. T

    Quantum Queries on the Harmonic Oscillator

    Hi folks, I wonder if I could run a few things past the quantum gurus among you - I'm just not quite convinced of some of the results I've been deriving. Homework Statement Consider the ground state of the simple harmonic oscillator at t = 0 with the normalised wave function...
  10. K

    Probability of Finding Particle in New Potential for Doubled Spring Constant

    Homework Statement particle in ground state of 1D harmonic oscillator - spring constant is doubled - what is the probability of finding the particle in the ground state of the new potential Homework Equations v=1/2kx^2 oscillator potential wavefunction ground state n=0 =...
  11. I

    How to Derive the Hamiltonian for a Two-Particle Harmonic Oscillator?

    Two particles are subjected to the same potential V=\frac{m \omega x^2}{2}. Particle one has with position x1 and momentum p1. Particle two has with position x2 and momentum p2. The problem asks how to show that the Hamiltonian is H=H_1+H_2 I am assuming that it is asking for a way to derive...
  12. E

    How Does an Electric Field Affect the Quantum Harmonic Oscillator?

    [SOLVED] QM simple harmonic oscillator Homework Statement If I have a particle in an SHO potential and an electric field, I can represent its potential as: V(x) = 0.5 * m \omega^2 (x - \frac{qE}{mw^2})^2 - \frac{1}{2m}(\frac{qE}{\omega})^2 I know the solutions to the TISE...
  13. I

    1-D simple harmonic oscillator

    I was just wondering what the difference was in the 1-D simple harmonic oscillator in the Heisenberg picture versus the Schrodinger picture?
  14. H

    Work done by a harmonic oscillator

    In the case of an undamped oscillator, the work done by the system is written as ( assume initial position is 0 ) : W = - \Delta U = - K \frac{x^2}{2} But to verify this , we must assume that the force acting on the oscillator is constant , which is not true as F = f(x) according to...
  15. M

    Kinetic and potential energy of harmonic oscillator

    Homework Statement Use ladder operator methods to determine the kinetic and potential energy of eigenstates of the harmonic oscillator.Homework Equations H=\frac{p^2}{2m} + \frac{1}{2}m\omega x^2 x=\sqrt{\frac{\hbar}{2m \omega}}(a+a^{\dagger})The Attempt at a Solution So I squared x, and then...
  16. E

    Turning points of a classical harmonic oscillator

    Homework Statement The turning points of a classical harmonic oscillator occur when the potential energy is equal to the total energy, correct? Homework Equations The Attempt at a Solution
  17. C

    What Does Isotropy Mean in a Two-Dimensional Harmonic Oscillator?

    Find the find the eigenfunctions and eigenvalues of a two-dimensional isotropic harmonic oscillator. I don't understand what does isotropic here mean. isotropic can be defined "not changing" when the coordinate change to any other position. Am I correct? Like mass, pressure...
  18. D

    Harmonic Oscillator wave function

    Uncertainty - Harmonic Oscillator The Wave function for the ground state of a quantum harmonic oscillator is \psi=(\alpha/\pi)^{1/4}e^{-\alpha x^2/2} where \alpha = \sqrt{ mk/ \hbar^2} . Compute \Delta x \Delta p known: Heisenberg Uncertainty Principle: \Delta p \Delta x >= \hbar/2...
  19. S

    Help with Linear Harmonic Oscillator Problem

    i m in a real problem and hav to give answers to the following problem tomorrow..please anyone help me.. Q: show that in ground state of linear harmonic oscillator ,the probability of finding oscillator outside the classical limit is nearly 17%?
  20. T

    A general math theory on the quantum harmonic oscillator?

    looking at the quantum mechanical harmonic oscillator, one has the differential equation in the form: \frac{d^2\psi}{du^2}+(\alpha-u^2)\psi=0 when a person who doesn't know any physics sees the equation, he will try a serial solution for psi, and he will find a solution with some recursive...
  21. 6

    How Does the Quantum Harmonic Oscillator Transition from U(x) to E?

    Can someone explain to me how they went from U(x)=(1/2)kx^2 to E=(n+1/2)(h/2pi)w? http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hosc.html
  22. M

    Harmonic Oscillator, Ladder Operators, and Dirac notation

    Defining the state | \alpha > such that: | \alpha > = Ce^{\alpha {\hat{a}}^{\dagger}} | 0 >\ ,\ C \in \mathbf{R};\ \alpha \in \mathbf{C}; Now, | \alpha > is an eigenstate of the lowering operator \hat{a}, isn't it? In other words, the statement that \hat{a} | \alpha >\ =\ \alpha | \alpha >...
  23. G

    Solving Proton Transfer with Harmonic Oscillator

    Hi, I am approximating a proton transfer from one water molecule to another. I would to have a quantum mechanical description of the proton transfer as a wavefunction. So I have approximated a "transition state" and use this as a harmonic potential. Then I get some energy values around this...
  24. V

    Is the Given Interaction Term Correct for Coupled Harmonic Oscillators?

    Homework Statement Find the energy levels and the wave functions of two harmonic oscillators of mass m_1and m_2, having identical frequencies \omega, and coupled by the interaction \frac{1}{2}k(x_{1}^{2}-x_{2}^{2})^2 Homework Equations Schrodinger equation. The Attempt at a...
  25. B

    How to Solve the Isotropic 3-D Harmonic Oscillator Using Frobenius’ Method?

    Homework Statement Use Frobenius’ method to solve the problem of the isotropic three dimensional harmonic oscillator in polar coordinates. It is sufficient to find the energy levels and degeneracies, but it would be nice to plot the spectrum like we did for hydrogen. Be sure to introduce...
  26. M

    Degeneracy of the 3d harmonic oscillator

    Hi! I'm trying to calculate the degeneracy of each state for 3D harmonic oscillator. The eigenvalues are En = (N + 3/2) hw Unfortunately I didn't find this topic in my textbook. Can somebody help me?
  27. C

    How Is the Angular Frequency of a Bead on a String Calculated?

    The problem is the following: a.) Obtain the equation of motion for the very small oscillations of a bead of mass m attached 1/5th of the way along a massless string of length 5l, which is under tension T. b.) Hence show that the angular frequency of oscillation is omega=sqrt(5T/4ml)...
  28. E

    Fractional energy in a damped harmonic oscillator

    Homework Statement Show that the fractional energy lost per period is \frac{\Delta E}{E} = \frac{2\pi b}{m\omega_0} = \frac{2\pi}{Q} where \omega_0 = \srqt{k/m} and Q = m\omega_0 / b Homework Equations E = 1/2 k A^2 e^{-(b/m)t} = E_0 e^{-(b/m)t} The Attempt at a Solution \Delta E = 1/2 k A^2...
  29. S

    Proving Delta x^2 & Delta p^2 for Harmonic Oscillator

    Homework Statement Show taht neither \Delta x nor \Delta p is generally constant (independant of time) for a general state of the one dimensional harmonic oscillator. Prove that (\Delta x)^2 and (\Delta p)^2 are both of the form (\Delta)^2 = A + B \cos^2 \omega t where omega is the...
  30. T

    Solving Psi(x,t) for a Harmonic Oscillator

    Hello, A harmonic oscillator is in the initial state: Psi(x, 0) = Phi_n (x) where Phi_n(x) is the nth solution of the time-independent Schr¨odinger equation. What is Psi(x, t)? Any clue? Thanks
  31. quasar987

    Explicit formula the nth eigenfunctions of the quantum harmonic oscillator?

    Hi, Is there an explicit formula for the eigenfunctions of the harmonic oscillator? By explicit, I mean "not written as the nth power of the operator (ax-d/dx) acting on the ground state". Thanks.
  32. J

    Hydrogen molecule as a harmonic oscillator

    Homework Statement The covalent bond between the two protons in the H2 molecule can be modeled by a harmonic spring with a spring constant k = 1100 N/m. a. What is the zero point energy of the H2 molecule as a harmonic oscillator? b. What is the energy of the first excited state...
  33. W

    Driven Damped Harmonic Oscillator Problem

    A mass m moves along the x-axis subject to an attractive force given by \frac {17} {2} \beta^2 m x and a retarding force given by 3 \beta m \dot{x}, where x is its distance from the origin and \beta is a constant. A driving force given by m A \cos{\omega t} where A is a constant, is applied to...
  34. D

    Driven Damped Harmonic Oscillator, f = ma?

    Driven Damped Harmonic Oscillator, f != ma?? Let's say I've got a driven damped harmonic oscillator described by the following equation: A \ddot{x} + B \dot{x} + C x = D f(t) given that f = ma why can't I write A \ddot{x} + B \dot{x} + C x = D ma substitute \ddot{x} = a to get A \ddot{x}...
  35. Y

    Harmonic oscillator outside classically allowed region

    the problem is as follows: in the ground state of the harmonic oscillator what is the probabilty of finding the particle outside the classically allowed region. where the classically allowed nrg is given by E=(1/2)m*omega^2*a^2 (where a is the amplitude). were given that...
  36. D

    Finding the Work of a Damped Harmonic Oscillator

    I'm trying to find the work done by a harmonic oscillator when it moves from x_{0} = 0 m to x_{max} = 1 m. The oscillator has initial velocity v_{0}, a maximum height of x_{max} = 1 m, initial height of x_{0} = 0 m, a spring constant of k, a mass of m = 1 kg, and a damping factor of b. It can...
  37. M

    Harmonic oscillator onboard a relativistic rocket

    Homework Statement We have a first frame S (named coordinate frame) at rest on the Earth (we suppose a non-rotating earht and this frame as a perfect inertial frame) and a second frame S' (named proper frame) moving in respect to the first with a constant relativistic velocity V along the...
  38. C

    Harmonic oscillator, friction, impulse

    Homework Statement A linear harmonic oscillator is subject to friction(stokes). The Oscillator gets an Impulse at the time t = 0 at the rest position. What is the equation of motion for the time interval 0 - t0?Homework Equations Friction force: Fr = -a * x'(t); a = constant (stokes friction)...
  39. C

    Calculating Amplitude and Initial Values in Simple Harmonic Oscillator

    A simple harmonic oscillator consists of a block of mass 2.60 kg attached to a spring of spring constant 380 N/m. When t = 2.30 s, the position and velocity of the block are x = 0.148 m and v = 4.080 m/s. (a) What is the amplitude of the oscillations? What were the (b) position and (c) velocity...
  40. L

    Harmonic oscillator expectation values

    I'm given that there is a harmonic oscillator in a state that is a superposition of the ground and first excited stationary states given by \psi = \frac{1}{\sqrt{2}}\abs{\psi_0(x,t) + \psi_1(x,t)}, where \psi_0 = \psi_0(x)e^{\frac{-iE_0t}{\hbar}} and \psi_1 = \psi_1(x)e^{\frac{-iE_1t}{\hbar}}...
  41. S

    3D harmonic oscillator ground state

    I've been told (in class, online) that the ground state of the 3D quantum harmonic oscillator, ie: \hat H = -\frac{\hbar^2}{2m} \nabla^2 + \frac{1}{2} m \omega^2 r^2 is the state you get by separating variables and picking the ground state in each coordinate, ie: \psi(x,y,z) = A...
  42. S

    Harmonic Oscillator Operators?

    I worked these problems out: [x, H] = xH - Hx = 0 [p, H] = pH - Hp = non-zero H is the harmonic oscillator Hamilitonian, x and p are the position and momentum operators, respectively. My question is, why doesn't p commute with H, but x does?
  43. A

    Interpreting the Harmonic Oscillator

    Ok - here goes: I see the energy levels of the harmonic oscillator as E = hw(n+1/2) = hwn + hw/2 (please ignore the lack of cool symbols) Now the hw/2 is something called the ground state - fine - no problem. Should I interpret homework as the fundamental harmonic? 2hw as the...
  44. M

    Harmonic Oscillator with fermions

    Hello... We have 3 fermions (s=1/2) at the ground state of a harmonic oscillator moving over the x-axis with a the classic hamiltonian for a three particle oscillator : H =(1/2m)*(P1)^2 +((1/2)*m(w^2)((x1)^2)) +(1/2m)*(P2)^2 +((1/2)*m(w^2)((x2)^2)) +(1/2m)*(P3)^2 +((1/2)*m(w^2)((x3)^2)) we...
  45. G

    How Many Quantum States Can Four Bosons Have in a Harmonic Oscillator?

    Suppose I have 4 bosons in a one-dimensional harmonic oscillator potential and that the total energy is E_\text{tot} = 8 \hbar \omega. Recall, E_n = (n+1/2)\hbar\omega. Question: How many quantum states exist? (assume no spin degeneracy) After accounting for the ground state, we have 6...
  46. S

    Energy values of a half harmonic oscillator

    energy values of a "half" harmonic oscillator This is the full question: Find the solution to the "half" harmonic oscillator: http://img241.imageshack.us/img241/9181/02bt7.jpg Compare the energy values and wave functions with those of the full harmonic oscillator. Why are some of the full...
  47. O

    Harmonic oscillator probability

    Hello all, if I have an ion trapped in a harmonic oscillator potential with a resonant frequency 0f 11 MHz and the ion cooled to a temperature of T=0.48mK, how do I find the probability that the oscillator is in its ground state? I know that the ground state energy is 1/2 \hbar \omega, but...
  48. Repetit

    Energy of the harmonic oscillator

    Hey! Can someone explain to why the energy of the harmonic oscillator must be at least: \frac{(\Delta p)^2}{2m}+\frac{1}{2}m \omega^2 (\Delta x)^2 I mean, \Delta x and \Delta p represents the uncertainty in the position and momentum, and therefore it does not really have anything to do...
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