Effective one-body dynamics in multiple-quantum NMR experiments

RUFEIL FIORI, ELENA; SÁNCHEZ, CLAUDIA M.; OLIVA, FABIANA Y.; PASTAWSKI, HORACIO M.; LEVSTEIN, PATRICIA R.

PHYSICAL REVIEW A - ATOMIC, MOLECULAR AND OPTICAL PHYSICS

American Physical Society

Año: 2009 vol. 79 p. 323241 - 323248

1050-2947

<!-- /* Font Definitions */ @font-face {font-family:"MS Sans Serif"; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"MS Sans Serif"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"MS Sans Serif"; mso-ansi-language:EN-US; mso-fareast-language:ES-AR;} h1 {mso-style-next:Normal; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; page-break-after:avoid; mso-outline-level:1; font-size:10.0pt; font-family:Arial; mso-font-kerning:0pt; mso-ansi-language:ES-TRAD; mso-fareast-language:ES-AR;} span.aps-boldfont1 {mso-style-name:aps-boldfont1; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt; font-weight:bold;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> A suitable NMR experiment in a one-dimensional dipolar coupled spin system allows one to reduce the natural many-body dynamics into effective one-body dynamics. We verify this in a polycrystalline sample of hydroxyapatite (HAp) by monitoring the excitation of NMR many-body superposition states: the multiple-quantum coherences. The observed effective one-dimensionality of HAp relies on the quasi-one-dimensional structure of the dipolar coupled network that, as we show here, is dynamically enhanced by the quantum Zeno effect. Decoherence is also probed through a Loschmidt echo experiment, where the time reversal is implemented on the double-quantum Hamiltonian, DQII+II. We contrast the decoherence of adamantane, a standard three-dimensional system, with that of HAp. While the first shows an abrupt Fermi-type decay, HAp presents a smooth exponential law.