What is Quantum well: Definition and 66 Discussions
A quantum well is a potential well with only discrete energy values.
The classic model used to demonstrate a quantum well is to confine particles, which were initially free to move in three dimensions, to two dimensions, by forcing them to occupy a planar region. The effects of quantum confinement take place when the quantum well thickness becomes comparable to the de Broglie wavelength of the carriers (generally electrons and holes), leading to energy levels called "energy subbands", i.e., the carriers can only have discrete energy values.
A wide variety of electronic quantum well devices have been developed based on the theory of quantum well systems. These devices have found applications in lasers, photodetectors, modulators, and switches for example. Compared to conventional devices, quantum well devices are much faster and operate much more economically and are a point of incredible importance to the technological and telecommunication industries. These quantum well devices are currently replacing many, if not all, conventional electrical components in many electronic devices.The concept of quantum well was proposed in 1963 independently by Herbert Kroemer and by Zhores Alferov and R.F. Kazarinov.
Homework Statement
An infinite quantum well width is 5 nm. An electron is confined in the well with 50% in the lowest eigenstate E1 and 50% in the second lowest state E2.
1. What is the energy difference between the two lowest states, E2-E1
2. What is the possible wavefunction of the...
Hiya guys, i have a quantum well in strange notation I have never seen before. I think i can do the question, i just need to know the shape of the well.
If someone would be so kind to draw me a shape (I think its a step but not sure?).
It is:
dphi dphi...
Thickness of Quantum Well ??
As I know there are two quantum wells exist.
1. Single Quantum Well
2. Multiple Quantum Well
My ques is that : How to find the thickness of a quantum well ? is there any equation to find quantum well thickness ? for single or multiple ?
Usually I have look...
Ok, so this example question is in my lecture notes:
Homework Statement
"For a 1-D quantum well, 5nm width, 2eV barrier height, calculate the number of energy levels in the well."
Homework Equations
So the equation given is a familiar one:
E_n=\frac{n^2 \pi^2 \hbar^2}{2 m L^2}...
1. What do we mean by the carrier number at transparency. I mean, what is carrier transparency of a laser?
2. in an IEEE paper ("Circuit Modeling of Quantum-Well Lasers for Optoelectronic Integrated Circuits (ICs) Including Physical Effect of Deep-Level Traps" IEEE J. Quantum electronics...
My understanding of a quantum well transistor is that it is created by sandwiching materials with higher bandgaps with smaller ones, so that it creates a potential well. So for instance, electrons will be forced to be confined within the well, as they would travel along the Quantum Well channel...
Homework Statement
V(x) = \inf if x \leq 0
= -V if 0 < x < a
= 0 if x > a
NOTE: E>V
Find the wave functions in each region and the stated phase shift.
Homework Equations
Schrodinger Eq.
Instructions note that wave functions are:
\Psi_I = A\sin{kx}
\Psi_{II} =...
Homework Statement
(a) Determine the reflectivity spectrum R(E) of a free particle of mass m reflected from an infinite jump V(x), where
V(x)=0 if x\leq0, V(x)=-\infty if x>0
The other similar problem is:
(b) Determine the energy levels of a particle of mass m confined to an infinite...
Does anyone knows how to solve the following eigenvalue equation using matlab? so as to obtain the energy levels in a quantum well structure.. or does anyone has the codes or knows where to find the codes to do so?
Eigenvalue equation:
tan(sq_root(2mE/hbar^2)*(d/2)) = sq_root((V-E)/E) for...
Does anyone knows how to solve the following eigenvalue equation using matlab? so as to obtain the energy levels in a quantum well structure.. or does anyone has the codes or knows where to find the codes to do so?
Eigenvalue equation:
tan(sq_root(2mE/hbar^2)*(d/2)) = sq_root((V-E)/E)...
I just took up my first course of quantum mechanics and i am having some serious problems solving quantum well problems.the thing is that after i take out the energy states of the well
and try to find K1 and K2 from it, the values i get are very very large.i think i am making a msitake with...
I just took up my first course of quantum mechanics and i am having some serious problems solving quantum well problems.the thing is that after i take out the energy states of the well
and try to find K1 and K2 from it, the values i get are very very large.i think i am making a msitake with...
suppose we have a single eigen-state finite potential well like following:
V(x)= V, x<-a and x>a;
0, -a<=x<=a;
say only one eigen-state within this well S1(x)
when all of sudden this potetial well broden by size of 2
V(x)= V, x<-2a and...