When we discussed the particle in a box model, we defined our
box to be from x=0 to x=a. Re-
examine this problem, defining the box to be from -a to +a. Recall
that the general solution for a
particle in a region of V=0 is ψ = A sin kx + B cos kx. Apply
the appropriate boundary conditions,
figure out what k is (in terms of a), and normalize your solution
(i.e. evaluate A and B).
.
When we discussed the particle in a box model, we defined our box to be from...
6. The Particle in a Box problem refers to a potential energy function called the infinite square well, aka the box: ; x < 0 (Region I) V(x) = 0 : 0 L (Region II) x x >L (Region III) Let's investigate a quantum particle with mass m and energy E in this potential well of length L We were unable to transcribe this image6d (continued) write down an equation relating ψ, (x = 0) to ψ"(x I and II....
The following information pertains to a particle in a 2-D box. Both dimensions of the box are equal (Lx=Ly=L) Normalized Eigen functions: 1. Ψ(x,y)= 2/L sin (nπx/L)sin( kπy/L) 2. H= h2/2m( d2/dx2+ d2/dy2)+ V (x,y) Boundary Conditions: V( x,y > 0; x,y < L) =0 V(x,y > L; x,y < 0 ) = Infinity a. Draw the 2-D potential energy surface ("box") that confines the particle. b. Use equations 2 and 3 to produce the general solution ( a formula in...
In solving the particle in a one dimensional infinite depth box problem (0k x < a) we started with the function following is a true statement? (a) The value of k is found by requiring that the solution be normalized. (b) The function wx) is not an eigenfunciton of the operator d2/dx2 (c) It is necessary that this function equals a when x=0 (ie, Ψ(0) = a). (d) The boundary condition at x = 0 is used to show that...
In class, we considered a box with walls at \(x=0\) and \(x=L\). Now consider a box with width \(L\) but centered at \(x=0\), so that it extends from \(x=-L / 2\) to \(x=L / 2\) as shown in the figure. Note that this box is symmetric about \(x=0 .\) (a) Consider possible wave functions of the form \(\psi(x)=A \sin k x\). Apply the boundary conditions at the wall to obtain the allowed energy levels.(b) Another set of possible wave functions...
21. For a particle of mass, m, moving along a circular path in the xy plane at a fixed distance, r, from the center and with no forces acting on it (V(x)-0), answer the following. Note the similarity to the hydrogen atom. We have an electron moving in the plane of a circle around a nucleus. Note the similarity between the Laplacian below and the azimuthal term in the hydrogen system Write the Schrödinger equation for this system. The Laplacian...
2. Derivation of the Kronig-Penney result: Write the solution for the wave function in the region 0 < r < a as a linear combi nation of sin and cos functions and in the region-b< 0 as a linear combination of the hvperbolic sin and cos functions: ψ(z) Asin Kr +Bcos Kx (0<x <a) = By invoking the continuity and differentiability conditions at a- 0, show that B D and AK - CQ, so essentially two constants, say A and...
(1 point) In this problem we find the eigenfunctions and eigenvalues of the differential equation B+ iy=0 with boundary conditions (0) + (0) = 0 W2) = 0 For the general solution of the differential equation in the following cases use A and B for your constants, for example y = A cos(x) + B sin(x)For the variable i type the word lambda, otherwise treat it as you would any other variable. Case 1: 1 = 0 (1a.) Ignoring the...
4. Answer the following short answer questions. a. For the particle in a square well, when solving Schrödinger equation in all regions, one gets the following wavefunctions (where A,B,C,D,F, and G are constants): 4.(x) = Ce** + De-*** (x) = A cos Bx + B sin Bx m(x) = Fe*:* + Ge-*** where Region 1/2 [2m(V. - E) (2mE ki and B = Since there are six unknown constants, one needs six boundary conditions/constraints to complete the problem. State the...
1. This problem is all about the variational method, as applied to the particle in a box. Remember that we discussed in class how to compute the variational energy for this problem, using (2) = x(L - 2) as the trial wavefunction. (a) Let's take instead the trial wavefunction (x) = x(L2 - 22). Sketch carefully this function from 0 to L, and show that it satisfies the particle in a box boundary conditions. (b) Compute the variational energy for...
Consider the Kronig-Penney model discussed in the lectures, where the periodic potential corresponds to an array of delta functions: However, unlike the usual model, we will take α < 0, so that we have potential wells rather than barriers. In the following, we aim to solve the time-independent Schrödinger equation 2m r (a) First consider the case where the energy E 0. Write down the general solution for ψ(z) within the interval 0 < r < a, and use the...