Quantum dot, quantum wire, quantum well?

[fisico30]

Hello Forum,
I understand that a quantum dot is a 3 dimensional confinement of an electron inside which the electron can only have quantized energy (quantized energy levels)...a quantum wire is a 2D trap, a well a 3D trap...

What is so special about confining electrons in space? Why so many applications derive from having atoms confined in space and having quantized energy...

Is the same thing happening inside single atoms? For instance, a hydrogen atom has a single electron that can move only among certain quantized energy levels...
In a conglomerate of many atoms together , like in a solid, we lose the concept of energy levels and we have bands of energy...

thanks
fisico30

 

[ahmedsbhe]

i help for calculated energy levels of quantum dots