Nuclear magnetic resonance (NMR) is one of the experimental schemes for quantum computation. Most initial state of quantum algorithm in NMR computation is the pseudopure state. Until now, there are several methods to ...Nuclear magnetic resonance (NMR) is one of the experimental schemes for quantum computation. Most initial state of quantum algorithm in NMR computation is the pseudopure state. Until now, there are several methods to prepare pseudopure state. This note, based on the idea of controlled-not (CNOT) gates combination, has analyzed the characteristics of this method in the odd- and even-qubit system. Also, we have designed the pulse sequence for a 4-qubit sample to obtain pseudopure state, and realized it in the experiment. This method reduces the complexity of experiment and gives a high signal-to-noise (S/N) ratio.展开更多
In this paper,the assignment of acomplex 8-spin-half system(7,7-dichloro-6-oxo-2-tio-bicycle[3.2.0]heptane-4-carboxlic acid)using nuclear magnetic resonance(NMR)techniques is presented and the hamiltonian obtained,was...In this paper,the assignment of acomplex 8-spin-half system(7,7-dichloro-6-oxo-2-tio-bicycle[3.2.0]heptane-4-carboxlic acid)using nuclear magnetic resonance(NMR)techniques is presented and the hamiltonian obtained,was used to demonstrate universal control.The system has 313C and 51H,in our work,we carried out traditional 1-D and 2-D experiments and also made use of coherent control together with simulation to get the full hamiltonian of this weakly coupled system.Spin-echo J-resolved 2-D experiments were used to obtain the heteronuclear and homonuclear coupling values;COSY45 experiments were used to obtain the signs of homonuclear coupling constants.The signs of heteronuclear coupling constants were obtained using the polarization transfer method.All the data obtained in the experiments were used in the simulation of the 1-D spectra and then optimized using the least square fitting method.After obtaining the full hamiltonian of the 8-spin system,we used it in QIP,prepared pseudopure states and implemented 1-qubit and 2-qubit gates on one of its 6-qubit subsystems.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.19974064).
文摘Nuclear magnetic resonance (NMR) is one of the experimental schemes for quantum computation. Most initial state of quantum algorithm in NMR computation is the pseudopure state. Until now, there are several methods to prepare pseudopure state. This note, based on the idea of controlled-not (CNOT) gates combination, has analyzed the characteristics of this method in the odd- and even-qubit system. Also, we have designed the pulse sequence for a 4-qubit sample to obtain pseudopure state, and realized it in the experiment. This method reduces the complexity of experiment and gives a high signal-to-noise (S/N) ratio.
文摘In this paper,the assignment of acomplex 8-spin-half system(7,7-dichloro-6-oxo-2-tio-bicycle[3.2.0]heptane-4-carboxlic acid)using nuclear magnetic resonance(NMR)techniques is presented and the hamiltonian obtained,was used to demonstrate universal control.The system has 313C and 51H,in our work,we carried out traditional 1-D and 2-D experiments and also made use of coherent control together with simulation to get the full hamiltonian of this weakly coupled system.Spin-echo J-resolved 2-D experiments were used to obtain the heteronuclear and homonuclear coupling values;COSY45 experiments were used to obtain the signs of homonuclear coupling constants.The signs of heteronuclear coupling constants were obtained using the polarization transfer method.All the data obtained in the experiments were used in the simulation of the 1-D spectra and then optimized using the least square fitting method.After obtaining the full hamiltonian of the 8-spin system,we used it in QIP,prepared pseudopure states and implemented 1-qubit and 2-qubit gates on one of its 6-qubit subsystems.
