Progress at Quantum Computing

NIST scientists have prepared a single qubit with an error rate, under 10^-4, that is low enough to enable error correction.

Because decoherence destroys the quantum information that is needed for the quantum algorithm that is supposed to run on the computer, scientists need to implement error correction to be able to implement a quantum algorithm. Therefore, this is an important step towards a working quantum computer.

The experiment which is published in the linked article achieved the low error rate by manipulating one trapped atom with microwaves instead of laser beams.

Quantum Computer Chip

One popular use for the quantum computer is the factorization of big numbers. If one could factor a big number as quickly as it can be multiplied from its prime components the RSA algorithm would be broken. Theory says that this should be possible, but no practical implementation has been seen so far. The most important obstacle is the quantum noise that leads to random changes in quantum states.

Researchers at the university of Bristol have found a way to cram a complete quantum computer on one silicon chip. However, the largest number they can factor right now is 15. Also, the peripheral devices still fill up a complete desktop.

In order to factor larger numbers the quantum computer needs more degrees of freedom, which are called 'qbits'. Miniaturizing the computer might help with increasing the number of qbits.