Method for effective pure states with any number of spins
Ushio Sakaguchi, Hiroshi Ozawa, Toshio Fukumi · Physical Review A · 2000
A method is proposed to prepare an effective pure state corresponding to the pure state $|0〉|0〉\ensuremath{\cdot}\ensuremath{\cdot}\ensuremath{\cdot}|0〉$ for any number of spins on a nuclear magnetic resonance quantum computer, where $|0〉$ stands for the spin-up state of a nuclear spin. The method is based on the spatial labeling proposed by Cory et al. [Proc. Natl. Acad. Sci. USA 94, 1634 (1997)].