DecoherenceFree Subspaces for Quantum Computation
Abstract
Decoherence in quantum computers is formulated within the semigroup approach. The error generators are identified with the generators of a Lie algebra. This allows for a comprehensive description which includes as a special case the frequently assumed spinboson model. A generic condition is presented for errorless quantum computation: decoherencefree subspaces are spanned by those states which are annihilated by all the generators. It is shown that these subspaces are stable to perturbations and, moreover, that universal quantum computation is possible within them.
 Publication:

Physical Review Letters
 Pub Date:
 September 1998
 DOI:
 10.1103/PhysRevLett.81.2594
 arXiv:
 arXiv:quantph/9807004
 Bibcode:
 1998PhRvL..81.2594L
 Keywords:

 Quantum Physics;
 Mathematical Physics
 EPrint:
 4 pages, no figures. Conditions for decoherencefree subspaces made more explicit, updated references. To appear in PRL