INVESTIGADORES
SEGNORILE Hector Hugo
congresos y reuniones científicas
Título:
Proton quantum quasi-equilibrium states in liquid crystals: Analytical ? Experimental study
Autor/es:
CLAUDIO J. BONIN; CECILIA E. GONZÁLEZ; HÉCTOR H. SEGNORILE; RICARDO C. ZAMAR
Lugar:
Montevideo
Reunión:
Congreso; XII Reunión de la SUF / 96ª Reunión Nacional de de Física de la AFA; 2011
Institución organizadora:
SUF / AFA
Resumen:
Proton
spins of liquid crystal (LC) molecules are small clusters of strongly
interacting spins (dipole-dipole), magnetically isolated in the average from
spins at other molecules, while mechanically coupled with an orientationally
ordered molecular environment. Previous work1 showed that quasi-equilibrium states
(quasi-invariants (QI)) associated with constants of motion of the residual
dipolar Hamiltonian HD0, can be prepared in LC through the
Jeener-Broekaert (JB) experiment2. An efficient application of the
QI in many fields, from the basic physics of open quantum systems and quantum
information processing, to the study of cooperative molecular dynamics, demands
a complete analytical description of these QI. We study
the proton spin dynamics and we report the first complete characterization of a
multi-spin-order QI in a spherical
tensor operator
basis, in a
4-spin-1/2 model, as a first approach for a typical LC (e.g. PAAd6). Following the behavior for long preparation
times, we observe that the experiments in PAAd6 cannot be explained
by assuming only two QI, demanding the consideration of additional QI's of more
complex tensor structure5.
REFERENCES
1- O. Mensio, C. E. González, and R. C. Zamar, Phys. Rev.
E 71, 011704(2005).
2- J. Jeener and P. Broekaert, Phys. Rev. 157,
232(1967).
3- H. Eisendrath, W. Stone and J. Jeener, Phys. Rev. B 17,
47(1978).
4- L. Buljubasich, G. Monti, R. H. Acosta, C. J. Bonin,
C. E. González, and R. C. Zamar, J. Chem. Phys. 130, 024501(2009) .
5- C. J. Bonin, PhD Thesis (2011) http://www.famaf.unc.edu.ar/publicaciones/documents/serie_d/DFis147.pdf
(cbonin@famaf.unc.edu.ar)
6- H. H. Segnorile, PhD Thesis (2009).