

X. The first energy correction E) to the 3rd Perturbation of Infinite Square Well. Consider this perturbation to the 1D...
Q4. Consider the 1D infinite square-well potential shown in the figure below. V(x) O0 Position (a) State the time-independent Schrödinger equation within the region 0<x<L for a particle with positive energy E 2 marks] (b) The wavefunction for 0<x< L can be written in the general form y(x) = Asin kx + B cos kx. Show that the normalised wavefunction for the 1D infinite potential well becomes 2sn'n? ?snT/where ( "1,2,3 ! where ( n = 1,2,5, ). [4 marks]...
4. 3D Infinite Square Well Perturbation (20 pts) Consider the three-dimensional infinite cubic well: otherwise The stationary states are where n, ny, and n, are integers. The corresponding allowed energies are Now let us introduce the perturbation otherwise a) Find the first-order correction to the ground state energy b) Find the first-order correction to the first excited state
4. 3D Infinite Square Well Perturbation (20 pts) Consider the three-dimensional infinite cubic well: otherwise The stationary states are where n, ny,...
Please answer a,b and c.
Now, consider a 1-d infinite square well of width a, between x = 0 and a, such that V(x) = 0 for 0<x<a and too elsewhere. A perturbation is then added to it so that V(x) = V. for 0 <x <a/2, and the same as before elsewhere. In other words, a flat bump of width a/2 and height V. in the left half of the well. (a) (5 pts) Carefully sketch the potential and...
An infinite square well and a finite square well in 1D with
equal width. The potential energies of these wells are
Infinite square well: V(x)=0, from 0 < x < a, also V(x) =
, elsewhere
Finite square well: V(x)= 0, from 0 < x < a, also V(x) =
,
elsewhere
The ground state of both systems have identical particles.
Without solving the energies of ground states, determine which
particle has the higher energy and explain why?
There is a 1-d infinite square well of width a, between x = 0 and a. We also know that V(x) = 0 for 0<x<a and +∞ elsewhere. Then we add a perturbation to it so that V(x) = ?_0 for 0 < x < a/2, and the same as before elsewhere. That is, a flat bump of width a/2 and height ?_0 in the left half of the well. Please answer following 3 questions. 1) Sketch the potential and...
Consider an infinite 1D square well with a length L with a particl of mass M trapped inside. (a) Calculate the expectation values(x), (2,2), (p), and (pay for the ground state where n 1. Note that the first three quantities may be calculate by using symmetry argu- ments, or by appealing to the fact that the kinetic energy is known exactly. On the other hand, to find (2) one will need to evaluate an integral. (b) Calculate ΔΧ-V(22)-(zy2 and ΔΙΕ...
Problem 3: Time-Independent Perturbation Theory Consider the particle in a 1D box of size L, as in Fig. 3. A perturbation of the form. V,δ ((x-2)2-a2) with a < L is applied to the unperturbed Hamiltonian of the 1D particle in a box (solutions on the equation sheet). Here V is a constant with units of energy. Remember the following propertics of the Dirac delta function m,f(x)6(x-a)dx f(a) 6(az) が(z) = = ds( dz E, or Ψ(x)-En 10 0.0 0.2...
4. (20 points). 5-function perturbation. Consider a particle in a one-dimensional infinite square well with boundaries at x--a and x-a. We introduce the following δ-function perturbation at V'(x) 00(z). a. Compute the first-order corrections to the energies of the particle induced by the perturbation b. Recall that you solved this problem exactly in problem set 4 (Griffiths 2.43). Compare your perturbation theory result to the exact solution
2. Calculate th first order energy shift for the first three states of the infinite square for 0-x-L. well in one dimension due to a ramp-shaped perturbation: V(r)- Use the following unperturbed eigenstates for the square well: Solution: The first order corrections for each state is given by E -(vn) 1, n°)), and there- fore: Sinn what happens to the sin4? 2 Vo L2 LL14
4. (20 points). δ. unction perturbation. Consider a particle in a one-dimensional infinite square well with boundaries at -a and-a. We introduce the following 6-function perturbation at x=0: a. Compute the first-order corrections to the energies of the particle induced by the ν' perturbation b. Recall that you solved this problem exactly in problem set 4 (Griffiths 2.43). Compare your perturbation theory result to the exact solution.