  The quantum-critical properties of the transverse-field Ising model with
algebraically decaying interactions are investigated by means of stochastic
series expansion quantum Monte Carlo, on both the one-dimensional linear chain
and the two-dimensional square lattice. We extract the critical exponents $\nu$
and $\beta$ as a function of the decay exponent of the long-range interactions.
For ferromagnetic Ising interactions, we resolve the limiting regimes known
from field theory, ranging from the nearest-neighbor Ising to the long-range
Gaussian universality classes, as well as the intermediate regime with
continuously varying critical exponents. In the long-range Gaussian regime, we
treat the effect of dangerous irrelevant variables on finite-size scaling
forms. For antiferromagnetic and therefore competing Ising interactions, the
stochastic series expansion algorithm displays growing auto-correlation times
leading to a reduced performance. Nevertheless, our results are consistent with
the nearest-neighbor Ising universality for all investigated interaction ranges
both on the linear chain and the square lattice.
