Consider the following statements regarding quantum dots : 1. A photon's polarization can be vertical or horizontal, or a superposition of both, and we can use this as a qubit. 2. Neutral atoms can be trapped at low temperatures using a magneto optical trap, which uses magnetic fields and lasers to cool and trap the atoms. 3. An electron can be bound to a small semiconductor device, similar to an electron bound to the nucleus of an atom. In these "artificial atoms", the spin of an electron, which can be "spin up" or "spin down", can be used as a qubit. Which of the above statements is/are correct ?