Harmonic oscillator Definition and 699 Threads

I'm looking at a question... The last part is this: find the expectation values of energy at t=0 The function that describes the particle of mass m is A.SUM[(1/sqrt2)^n].\varphi_n where I've found A to be 1/sqrt2. The energy eigenstates are \varphi_n with eigenvalue E_n=(n + 1/2)hw...

Quantum Harmonic Oscillator Operator Commution (solved) EDIT This was solved thanks to CompuChip! The entire post is also not very interesting as it was a basic mistake :P No need to waste time This is not homework (I am not currently in college :P), but it is a mathematical question I'm...

Ok, so I am trying understand how to derive the following version of the Schrodinger Equation for QHO: \frac{d^2u}{dz^2} + (2\epsilon-z^2)u=0 where \ 1. z=(\frac{m\omega}{hbar})^{1/2}x and \ 2. \epsilon= \frac{E}{hbar\omega} I've started with the TISE, used a potential of...

Homework Statement This is for my mechanics class. It seems like it should be easier than I'm making it. A single object of mass m is attached to the ends of two identical, very long springs of spring constant k. One spring is lined up on the x-axis; the other on the y-axis. Chpose your...

Homework Statement Consider a harmonic oscillator with mass=0.1kg, k=50N/m , h-bar=1.055x10-34 Let this oscillator have the same energy as a mass on a spring, with the same k and m, released from rest at a displacement of 5.00 cm from equilibrium. What is the quantum number n of the state of...

An experimenter has carefully prepared a particle of mass m in the first excited state of a one dimensional harmonic oscillator. Suddenly he coughs and knocks the center of the potential a small distance, a, to one side. It takes him a time T to recover and when he has done so he immediately...

This is not really homework, just a project I'm toying with in my sparetime. I'm doing some Path Integral Monte Carlo simulations, for now just for the 1D quantum harmonic oscillator. Anyways, currently I compare my results to the analytic mean energy of a 1D quantum harmonic oscillator, given...

Find the time dependence of the expectation value <x> in a quantum harmonic oscillator, where the potential is given by V=\frac{1}{2}kx^2 I'm assuming some wavefunction of the form \Psi(x,t)=\psi(x) e^{-iEt/\hbar} When I apply the position operator, I get: <x>=\int_{-\infty}^\infty...

Homework Statement P4-1. The Method of Frobenius: Sines and Cosines. The solutions to the differential equation y"+ y = 0 can be expressed in terms of our familiar sine and cosine: y(x) = Acos(x) + Bsin(x) . Use the Method of Frobenius to solve the above differential equation for the even...

I Have a brief idea about the equation and i have searched the web for its application to one dimensional harmonic oscillator but no use. Any Help Would Be Welcomed Especially about the latter:smile:

Homework Statement I have a simple harmonic oscillator system with the driving force a sinusoidal term. The question is to find the general solution and the amplitude of the steady state solution Homework Equations I found the steady state part of the solution. It is of the form...

I know that the HO hamiltonian in matrix form using the known eigenvalues is <i|H|j> = E^j * delta_ij = (j+1/2)hbar*omega*delta_ij, a diagonalized matrix. How do I set up the non-diagonalized matrix from the potential V=1/2kx^2?

Homework Statement Does a wavefunction have to be normalized before you can calculate the probability density? Homework Equations n/a The Attempt at a Solution Im thinking yes? so that your probability will be in between 0 and 1?

Homework Statement Calculate the ratio of the kinetic energy to the potential energy of a simple harmonic oscillator when its displacement is half its amplitude. Homework Equations KE=1/2mv2 = 1/2kA2sin2(wt) U=1/2kx2 = 1/2kA2cos2(wt) KEmax=1/2kA2 Umax=1/2KA2 The Attempt at a...

Homework Statement Consider a particle of mass m moving in a one-dimensional potential, V(x)=\infty for x\leq0 V(x)=\frac{1}{2}m{\omega^2}{x^2} for x>0 This potential describes an elastic spring (with spring constant K = m\omega^2) that can be extended but not compressed. By...

Hi, I'm desperately searching for some literature which discusses the harmonic oscillator, preferably simple, in terms of the path integral formulation. I am unfamiliar with dirac notation and want something as simple as possible which gives general results of the harmonic oscillator in terms of...

Homework Statement A quantum mechanical harmonic oscillator with resonance frequency ω is placed in an environment at temperature T. Its mean excitation energy (above the ground state energy) is 0.3ħω. Determine the temperature of this system in units of its Einstein-temperature ΘE = ħω/kB...

Homework Statement One possible solution for the wave function ψn for the simple harmonic oscillator is ψn = A (2*αx2 -1 ) e-αx2/2 where A is a constant. What is the value of the energy level En? Homework Equations The time independent Schrodinger wave equation d2ψ / dx2 =...

Hi everyone, I'm dealing with system identification for the first time in my life and am in desperate need of help :) The system is spring-mounted and I'm analyzing the vertical and torsional displacements. However, it seems like the vertical and torsional oscillations are coupled (shouldn't...

I've been looking at a coupled harmonic oscillator, and normal modes of this: http://en.wikipedia.org/wiki/Normal_mode#Example_.E2.80.94_normal_modes_of_coupled_oscillators At the bottom of this example it says: This corresponds to the masses moving in the opposite directions, while the...

Homework Statement Particle mass m is confined by a one dimensional simple harmonic oscillator potential V(x)=Cx2, where x is the displaecment from equilibrium and C is a constant By substitution into time-independant schrodingers with the potential show that \psi(x)=Axe-ax2 is a...

The problem is: Two damped harmonic oscillator are coupled. Both oscillators has same natural frequency \omega_0 and damping constant \beta. 1st oscillator is damped by 2nd oscillator. Damping force is proportional to velocity of 2nd oscillator. And, vice versa, 2nd oscillator is...

Homework Statement Show simple harmonic motion starting from Hooke's Law. The Attempt at a Solution F=-kx =m\frac{d^2x}{dt^2}=-kx \frac{1}{x}\frac{d^2x}{dt^2}=-\frac{k}{m} =\frac{1}{x}\frac{d}{dt}\frac{dx}{dt}=-\frac{k}{m}...

Homework Statement A charged harmonic oscillator is placed in an external electric field \epsilon i.e. its hamiltonian is H = \frac{p^2}{2m} + \frac{1}{2}m \omega ^2 x^2 - q \epsilon x Find the eigenvalues and eigenstates of energy Homework Equations The Attempt at a Solution...

Homework Statement Prove that a 1-d harmonic oscillator in ground state obeys the HUP by computing delta P sub x and delta X Homework Equations delta x = sqrt(<x^2>-<x>^2) delta px = sqrt(<px^2>-<px>^2) The Attempt at a Solution I have absolutely no idea where to start with...

Homework Statement A particle of mass m moves (in the region x>0) under a force F = -kx + c/x, where k and c are positive constants. Find the corresponding potential energy function. Determine the position of equilibrium, and the frequency of small oscillations about it. The Attempt at a...

Homework Statement A particle with with the mass of m is attached to a spring (with no mass, spring constant k, length l) which is attached to a wall. The particle is moving with no friction along the x-axis. a) Write the particles motion equation, and find the general solution to the motion...

Homework Statement The ground state wave function of a one-dimensional simple harmonic oscillator is \varphi_0(x) \propto e^(-x^2/x_0^2), where x_0 is a constant. Given that the wave function of this system at a fixed instant of time is \phi\phi \propto e^(-x^2/y^2) where y is another...

Homework Statement This is a 3 part problem, mass M on a spring of length l with mass m. The first part was to derive the Kinetic Energy of one segment dy, second part was to Integrate this and get the Kinetic Energy of (1/6)m(V^2) where V is the velocity of the Mass M at the end of the...

Homework Statement Find the eigenvalues and eigenfunctions of H\hat{} for a 1D harmonic oscillator system with V(x) = infinity for x<0, V(x) = 1/2kx^2 for x > or equal to 0. Homework Equations The Attempt at a Solution I think the hamiltonian is equal to the potential + kinetic...

Hello everybody, I noticed these questions are lengthy. If you want to skip my introduction, just scroll down to the questions. I put *** next to each one. I just started Quantum Theory I this semester and I have a question (actually two questions) regarding the quantum harmonic...

http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hosc4.html#c1 I know the energy should be E = \frac{{{p^2}}}{{2m}} + \frac{1}{2}m{\omega ^2}{x^2} But I can't figure out why the minimum energy is related to \Delta p

Homework Statement "Show that the ratio of two successive maxima in the displacement of a damped harmonic oscillator is constant."Homework Equations x = a e^(-\upsilont/2) cos (\omegat - \vartheta)The Attempt at a Solution So I want to find when this beast has its maximum values, so I take the...

Hello PF members, Is there some good book, which contain the derivation of average energy of a harmonic oscillator at temperature T. I want to derive from Planck's distribution (PD) function (<n>=(exp(##\hbar\omega/kT##)-1)##^{-1}##)...to get the following relation: energy E=...

Homework Statement Calculate the quantized energy levels of a linear harmonic oscillator of angular frequency $\omega$ in the old quantum theory. Homework Equations \[ \oint p_i dq_i = n h \] The Attempt at a Solution This is supposed to be a simple "exercise" (the first in...

Homework Statement use the hamiltonian equation H=H_x+H_y+H_z to show that wave functions of the form \varphi(r)=\phii(x)\phij(y)\phik(z) where the functions phi_i(x) are the energy eigenfunctions for a 1-d SHM , satisfy H*phi=E*phi , and find the followed values of E for the 3-d...

Homework Statement I wonder if someone could help me to arrive at equation 2.56 by performing the substitutions. Please see the attachment Homework Equations Please see the attachment for this part. and also for the attempt of a solution.

I'm trying to read through Griffiths' QM book, and right now I'm on the series solution to the harmonic oscillator (ch 2). I'm having a hard time following the math (especially after equation 2.81) in this section, so if anyone has read this book, please help. My first question is about the...

I've followed this: http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hosc3.html#c1, up to the part where it gets to here: . The guide says: "Then setting the constant terms equal gives the energy"? Am I being stupid? I really can't see where that equations come from.

I am not really asking how to solve the problem but just for explanation of what I know to be true from the problems solution. Basically the original problem statement is this: A particle in a harmonic oscillator potential starts out in the state |psi(x,0)>=1/5 * [3|0> + 4|1>] and it asks to...

Hi, I'm trying to learn quantum physics (chemistry) on my own so that my work with Gaussian and Q-Chem for electronic structural modeling is less of a black box for me. I've reached the harmonic oscillator point in McQuarrie's Quantum Chemistry book and I'm having trouble justifying a step in...

Homework Statement I have to find the minimum and maximum values of the uncertainty of \Deltax and specify the times after t=0 when these uncertainties apply. Homework Equations The wave function is Ψ(x, 0) = (1/√2) (ψ1(x)+ iψ3(x)) and for all t is Ψ(x, t) = (1/√2)...

1. Explain why any term (such as AA†A†A†)with unequal numbers of raising and lowering operators has zero expectation value in the ground state of a harmonic oscillator. Explain why any term (such as AA†A†A) with a lowering operator on the extreme right has zero expectation value in the...

Homework Statement Calculate the expected value of the kinetic energy being \varphi(x,0)=\frac{1}{\sqrt{3}}\Phi_0+\frac{1}{\sqrt{3}}\Phi_2-\frac{1}{\sqrt{3}}\Phi_3 Homework Equations K=\frac{P^2}{2m} The Attempt at a Solution I tried to solve it using two diffrent methods and...

Homework Statement Consider a particle of mass m moving in a 3D potential V(\vec{r}) = 1/2m\omega^2z^2,~0<x<a,~0<y<a. V(\vec{r}) = \inf, elsewhere. 2. The attempt at a solution Given that I know the solutions already for a 1D harmonic oscillator and 1D infinite potential well I'm going to...

Why does in QM the electron does not fall toward the nucleus? After all, the only force between nucleus and electron is attractive. It seems that the electron can and does indeed fall toward the center in <simple harmonic oscillator>? My question is what's so different in these two systems...

Homework Statement Trying to normalize the first excited state. I have, 1 = |A_1|^2(i\omega\sqrt{2m}) \int_{-\inf}^{\inf} x \exp(-m\omega x^2/2\hbar) How do I do the integral so I don't get zero since it's an odd funciton?

My question is pretty easy (i think). I have a wavefcn PSI defined at t=0. The PSI is a mix of several eigenstates. Let's say PHI(x,0)=C1phi1 + C2 phi3. Now C1 and C2 are given to me, so I am wondering is this wavefcn. already normalized, or do i have to normalize it despite definite C1 and C2...

Hi! Would anyone be able to point me toward a detailed explanation of determining the Hamiltonian of a polyatomic quantum oscillator? My current text does not explain the change of coordinates ("using normal coordinates or normal modes") in detail. All I can find is material on a diatomic...

Can someone tell me if there is a difference in the moving motion between a quantum harmonic oscillator and a simple harmoic oscillator. Also, does anoyone know a good site where i could learn more on quantum harmonic oscillator. ty