  * The article is not quite correct. Decoherence times can range from picoseconds to seconds, depending on the physical system used to implement quantum computer. I think the statement about one nanosecond refers to a different physical system than the one used to build 7 qubit computer. I should go to library, check all the details and rewrite this.   :Error correction can be used to protect against decoherence but was not used in the 7 qubit experiment. 