Error Avoiding Quantum Codes
Paolo Zanardi, Mario Rasetti · Modern Physics Letters B · 1997
The existence is proved of a class of open quantum systems that admits a linear subspace [Formula: see text] of the space of states such that the restriction of the dynamical semigroup to the states built over [Formula: see text] is unitary. Such subspace allows for error-avoiding (noiseless) encoding of quantum information.