27 April 2012

Quantum Wells, quantum wires and quantum dots

When the size of a material is continuously reduced from a bulk or macroscopic size, such as a meter or a centimetre, to a very small size, the properties remain same at first, then small changes begin to occur, until finally when the size drops below 100nm dramatic changes in properties can occur.

Quantum Well :

If one dimension is reduced to the nanorange while the other two dimensions remain large, then we obtain a structure known as a quantum well.

Quantum wire :

If two dimensions are reduced to the nanorange and one remains large, the resulting structure is called as a quantum wire.

Quantum dot :

The process of size reduction in which all three dimensions leads to low nanometer range is referred as a quantum dot.

       The word quantum is associated with these three types of nanostructures because the changes in properties arise from quantum physics in the domain of nanorange.