CURRENT AND CONDENSATE DISTRIBUTIONS IN ROTATIONAL EXCITED-STATES OF QUANTUM LIQUID CLUSTERS

Recent quantum Monte Carlo calculations of small quantum clusters have shown that it is feasible to study their rotationally excited states directly. [M. A. McMahon, R. N. Barnett, and K. B. Whaley, J. Chem. Ph ys. 99, 8816 (1993).] We extend this work by sampling, from optimized variational wave functions, the current and Bose condensate distributi ons in (He-4)(7), (H-2)(7), and (He-4)(40) clusters. We demonstrate th at these distributions are useful tools in identifying the location an d nature of rotational excitations. With different constructions of ro tational wave functions, the excitations can be either localized (as s urface modes),or delocalized throughout the cluster analogous to the b ulk superfluid vortex states. Condensate depletions in the excited sta tes are observed, except for the delocalized excitation, where we find a higher condensate fraction than in the ground state. (C) 1996 Ameri can Institute of Physics.