  We study hard core bosons on a two leg ladder lattice under the orbital
effect of a uniform magnetic field. At densities which are incommensurate with
flux, the ground state is a Meissner state, or a vortex state, depending on the
strength of the flux. When the density is commensurate with the flux,
analytical arguments predict the existence of a ground state of central charge
$c = 1$, which displays signatures compatible with the expected Laughlin state
at $\nu=1/2$. This differs from the coupled wire construction of the Laughlin
state in that there exists a nonzero backscattering term in the edge
Hamiltonian. We construct a phase diagram versus density and flux in order to
delimit the region where this precursor to the Laughlin state is the ground
state, by using a combination of bosonization and numerics based on the density
matrix renormalization group (DMRG) and exact diagonalization. We obtain the
phase diagram from local observables and central charge. We use bipartite
charge fluctuations to deduce the Luttinger parameter for the edge Luttinger
liquid corresponding to the Laughlin state. The properties studied with local
observables are confirmed by the long distance behavior of correlation
functions. Our findings are consistent with a calculation of the many body
ground state transverse conductivity in a thin torus geometry for parameters
corresponding to the Laughlin state. The model considered is simple enough such
that the precursor to the Laughlin state could be realized in current ultracold
atom, Josephson junction array, and quantum circuit experiments.
