"In the UNSW experiment, the two quantum particles involved are an electron and the nucleus of a single phosphorus atom, placed inside a silicon microchip. These particles are, literally, on top of each other - the electron orbits around the nucleus. Therefore, there is no complication arising from the spookiness of action at a distance.
"However, the significance of the UNSW experiment is that creating these two-particle entangled states is tantamount to writing a type of computer code that does not exist in everyday computers. It therefore demonstrates the ability to write a purely quantum version of computer code, using two quantum bits in a silicon microchip - a key plank in the quest super-powerful quantum computers of the future.
"In a normal computer, using two bits, one could write four possible code words: 00, 01, 10 and 11. In a quantum computer, instead, one can also write and use 'superpositions' of the classical code words, such as (01 + 10), or (00 + 11). This requires the creation of quantum entanglement between two particles.
"These codes are perfectly legitimate in a quantum computer, but don't exist in a classical one," said UNSW Research Fellow Stephanie Simmons, the paper's co-author. "This is, in some sense, the reason why quantum computers can be so much more powerful: with the same number of bits, they allow us to write a computer code that contains many more words, and we can use those extra words to run a different algorithm that reaches the result in a smaller number of steps.""