Fast preparation method of effective pure states for NMR‐quantum computer with controlled‐not gates
Minaru Kawamura, Ryuichi Sawae, Takashi Kumaya, Kenichi Takarabe, Yoshinori Manmoto, Toshio Sakata · International Journal of Quantum Chemistry · 2004
Abstract A fast method to prepare effective pure states for NMR‐quantum computer in homo‐nuclear spin system is proposed. The temporal averaging method has been introduced to prepare an effective pure state in NMR‐quantum computer, but the method requires many experiments, whose number increases exponentially with the number of quantum bits (qubits), and it seems that a huge number of logical gates are required. The proposed method avoids this problem by eliminating a part of elements in the density matrices. This method requires only one ancillary qubit and two different experiments; the steps have been confirmed to be proportional to the number of qubits up to four‐qubit. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004