American Physical Society, Physical Review Letters, 15(63), p. 1601-1604, 1989
DOI: 10.1103/physrevlett.63.1601
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Path-integral Monte Carlo calculations have been used to study 4He clusters at low temperatures. We develop a fluctuation formula for the superfluid fraction in terms of a projected area swept out by a path. Manifestations of superfluid behavior are shown to exist in a cluster of 64 atoms and a remnant of the lambda transition persists in a cluster of 128 atoms. The temperature dependence of the superfluid fraction is similar to that observed in the liquid.