Volume 122, Issue 4, 22 January 2005
Index of content:
122(2005); http://dx.doi.org/10.1063/1.1850456View Description Hide Description
Pseudopure states of a system of twelve interacting spins are experimentally demonstrated. The system is a cluster of dipolar-coupled nuclear spins of fully labeled -benzene in a liquid crystalline matrix. At present, this is the largest and the most complex composite system where individual quantum states have been addressed.
122(2005); http://dx.doi.org/10.1063/1.1850905View Description Hide Description
Expanding the wave functions of the ground and excited states of (or in terms of spherically symmetric explicitly correlated Gaussian functions with preexponential multipliers consisting of powers of the internuclear distance, and using the variational method, we performed very accurate nonadiabatic calculations of all bound states of this system corresponding to the zero total angular momentum quantum number (vibrational states; The total and the transition energies obtained agree with the best available calculations. For each state we computed the expectation values of the and interparticle distances. This is the first time these quantities were computed for using rigorous nonadiabaticwave functions. While up to the state some asymmetry is showing in the and distances, for and we observe a complete breakdown of the Born–Oppenheimer approximation and localization of the electron almost entirely at the deuteron.
122(2005); http://dx.doi.org/10.1063/1.1850899View Description Hide Description
An exact quantum master equation formalism is constructed for the efficient evaluation of quantum non-Markovian dissipation beyond the weak system-bath interaction regime in the presence of time-dependent external field. A novel truncation scheme is further proposed and compared with other approaches to close the resulting hierarchically coupled equations of motion. The interplay between system-bath interaction strength, non-Markovian property, and required level of hierarchy is also demonstrated with the aid of simple spin-boson systems.