Method of multifrequency excitation for creating pseudopure states for NMR quantum computing
Anatoly K. Khitrin, Hong Yue Sun, B. M. Fung · Physical Review A · 2001
An alternative method of preparing pseudopure states for NMR quantum computing is presented. The method involves population transfer by the use of a multifrequency excitation pulse. The system studied was a spin-7/2 nucleus ${(}^{133}\mathrm{Cs})$ in a liquid-crystalline environment. It is shown that all eight pseudopure quantum states for this three-qubit system can be prepared by using only 1--3 pulses, while the intensities of the relevant peaks increase by a factor of up to 4 compared to the equilibrium NMR spectrum. A comparison of the intensity enhancement by population transfer for quadrupolar nuclei and that for coupled spin-1/2 systems is given.