Using atomically precise growth techniques of oxide thin film, there has been a huge interest in combining different oxides to create heterostructures with unique properties which are distinct from the properties of individual materials. These man-made heterostrucutres of oxide show fascinating new physics, as well as having technological application for future electronics.

I will begin by giving a general introduction to this filed, and the pulsed laser deposition technique that is commonly used to fabricate heterostructured oxide thin film. Following this, I will focus on the case of oxide quantum well of Nb-doped SrTiO3 (Nb:SrTiO3) embedded in insulating SrTiO3. This system exhibits a superconducting transition around 0.3 K and 3D to 2D crossover in superconductivity by controlling thickness. In addition, 2D quantum oscillation of Shubnikov de-Hass type can be observed above the upper critical field.
Finally I will briefly discuss the characteristics of the two dimensional superconducting state that is found in LAO/STO interface below 0.5 K, and can be controlled with a gate electric field.