  We consider the large-charge expansion of the charged ground state of a
Schrodinger-invariant, nonrelativistic conformal field theory in a harmonic
trap, in general dimension d. In the existing literature, the energy in the
trap has been computed to next-to-leading order (NLO) at large charge Q, which
comes from the classical contribution of two higher-derivative terms in the
effective field theory. In this note, we explain the structure of operators
localized at the edge of the droplet, where the density drops to zero. We list
all operators contributing to the ground-state energy with nonnegative powers
of Q in the large-Q expansion. As a test, we use dimensional regularization to
reproduce the calculation of the NLO ground state energy by Kravec and Pal ,
and we recover the same universal coefficient for the logarithmic term as in
that work. We refine the derivation by presenting a systematic operator
analysis of the possible edge counterterms, showing that different choices of
cutoff procedures must yield the same renormalized result up to an enumerable
list of Wilson coefficients for conformally invariant local counterterms at the
droplet edge. We also demonstrate the existence of a previously unnoticed edge
contribution to the ground-state operator dimension of order Q^{{2\over 3} -
{1\over d}} in d spatial dimensions. Finally, we show there is no bulk or edge
counterterm scaling as Q^0 in two spatial dimensions, which establishes the
universality of the order Q^0 term in large-Q expansion of the lowest charged
operator dimension in d=2.
