Relaxation of coherent states in a two-qubit NMR quadrupole system
- Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150, Rio de Janeiro 22290-180 (Brazil)
- Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Sao Carlos, P.O. Box 369, Sao Paulo 13560-970 (Brazil)
- Departamento de Fisica, Universidade Federal do Espirito Santo, Vitoria, Espirito Santo 29060-900 (Brazil)
We report a detailed study of the longitudinal relaxation of several coherent states on the nuclear-magnetic-resonance (NMR) two-qubit quadrupole system, {sup 23}Na (spin 3/2) in a lyotropic liquid-crystal system at room temperature. Relaxation of pseudopure states, simulated pseudo-Bell states and Hadamard states were investigated. The coherence of superposition states was verified by applying the respective quantum ''reading'' operators and comparing the recovered state with the original one. The degree of recovery varies between {approx_equal}70% and {approx_equal}100%, depending on the time length of the gate, as compared to relaxation times. Spin-lattice relaxation results follow a recently proposed multiexponential model that includes mixed magnetic dipolar and electric quadrupolar interactions. Relaxation curves are governed by initial conditions, and from the experimental curves individual transition rates are derived. The transverse relaxation time constant T{sub 2} is found not to depend on the initial distribution of populations. This is a systematic study of relaxation in the context of NMR quantum computing.
- OSTI ID:
- 20640027
- Journal Information:
- Physical Review. A, Vol. 68, Issue 2; Other Information: DOI: 10.1103/PhysRevA.68.022311; (c) 2003 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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