  We present extensive new direct path-integral Monte Carlo results for
electrons in quantum dots in two and three dimensions. This allows us to
investigate the nonclassical rotational inertia (NCRI) of the system, and we
find an abnormal negative superfluid fraction [Phys. Rev. Lett. 112, 235301
(2014)] under some conditions. In addition, we study the structural properties
by computing a sophisticated center-two particle correlation function.
Remarkably, we find no connection between the spatial structure and the NCRI,
since the former can be nearly identical for Fermi- and Bose-statistics for
parameters where the superfluid fraction is diverging towards negative
infinity.
