Quantum Scattering: Finding E0 & Estimating Fraction of Particles Transmitted

In summary, a beam of particles with mass m and energy E0 is incident on a square potential energy well of width L and depth V0. The potential energy outside the well is zero and E0 is the lowest energy at which a transmission resonance occurs with 100% of the beam being transmitted and none reflected. In part (a), a second beam with energy E1 is incident on a square potential energy barrier of width L and height V0, with the potential energy outside the barrier also being zero. The question asks for the lowest value of E1 at which a transmission resonance occurs with 100% of the beam being transmitted and none reflected, expressed in terms of E0 and V0. In part (b), a third
  • #1
cleggy
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Homework Statement



A beam of particles, each of mass m and energy E0,is incident on a square potential energy well of width L and depth V0,where 0 <V0 < h(bar)^2[tex]\pi[/tex]^2/2mL^2 . Outside the region of the well, the potential energy is equal to zero. Suppose that E0 is the lowest energy at which a transmission resonance occurs, with 100% of the beam being transmitted and none reflected.

(a)
A second beam of particles, each of mass m and energy E1 is incident
on a square potential energy barrier of width L and height V0. Outside the
region of the barrier, the potential energy is equal to zero. What is the
lowest value of E1 at which a transmission resonance occurs in this
situation, with 100% of the beam being transmitted and none reflected?
Express your answer in terms of E0 and V0.
(b)
A third beam of particles, each of mass m and energy V0/2is
incident on a square potential energy barrier of width L and height V0.
Outside the region of the barrier, the potential energy is equal to zero.
Estimate the fraction of particles that tunnels through the barrier if
V0 =1.0h(bar)^2/mL^2 .
(c)
Suppose that the barrier in part (b) extends from x =0 to x = L and the incident beam travels in the positive x-direction. For x< 0 the energy eigenfunction describing the beam is Aexp(ikx) + Bexp(−ikx), while for x>L it is Fexp(ikx),where k is the wave number and A, B and F are constants. For the conditions described in part (b), what is the value of the ratio |F|/|B|?


Homework Equations





The Attempt at a Solution



Can someone give me help with starting this please?

Is the lowest energy E0 = V0/2 ?

if so how is this derived?
 
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  • #2
first you need to sketch the problem, so you can understand it well [I've done it for you:smile:], apparently you have three zones as shown bellow

in a general matter, you have to solve the Schrödinger equation in the x direction, you should have 3 equations for this system [one for each zone], you also need to consider the primary conditions to solve it.

hint: with the beam being 100% transmitted, what do you think the energy of the particles in this system should be, E>Vo or E<Vo?
 

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FAQ: Quantum Scattering: Finding E0 & Estimating Fraction of Particles Transmitted

1. What is quantum scattering and why is it important?

Quantum scattering is the study of how particles interact and scatter off of each other at a quantum level. It is important because it helps us understand the fundamental laws of nature and can be applied in fields such as nuclear physics and quantum computing.

2. How is E0 calculated in quantum scattering?

E0, or the scattering energy, is calculated using the Schrodinger equation and the potential energy between the particles. This equation takes into account the initial kinetic energy of the particles and the potential energy they will experience as they interact.

3. What is the role of the transmission coefficient in quantum scattering?

The transmission coefficient is a measure of the fraction of particles that are transmitted through a potential barrier. It helps us understand how likely it is for a particle to pass through a certain region of space and can give insight into the properties of the barrier.

4. How can we estimate the fraction of particles transmitted in quantum scattering?

We can estimate the fraction of particles transmitted by using the transmission coefficient and the initial and final energies of the particles. This can be done by solving the Schrodinger equation and using the transmission coefficient to calculate the probability of transmission.

5. What factors can affect the accuracy of our calculations in quantum scattering?

There are several factors that can affect the accuracy of our calculations in quantum scattering, such as the complexity of the potential energy function, the number of particles involved, and the precision of our measurements. Additionally, external factors such as environmental noise can also impact the accuracy of our results.

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