Are All Noisy Quantum States Obtained from Pure Ones?

Henderson, LeahLinden, NoahPopescu, Sandu2004-12-032004-12-0320012001http://hdl.handle.net/2003/180410.17877/DE290R-11552enThe American Physical SocietyPhysical Review Letters530Are All Noisy Quantum States Obtained from Pure Ones?10.1103/PhysRevLett.87.237901article (journal)