  We put forward the idea of lattice quantum magnetometry, i.e. quantum sensing
of magnetic fields by a charged (spinless) particle placed on a finite
two-dimensional lattice. In particular, we focus on the detection of a locally
static transverse magnetic field, either homogeneous or inhomogeneous, by
performing ground state measurements. The system turns out to be of interest as
quantum magnetometer, since it provides a non-negligible quantum Fisher
information (QFI) in a large range of configurations. Moreover, the QFI shows
some relevant peaks, determined by the spectral properties of the Hamiltonian,
suggesting that certain values of the magnetic fields may be estimated better
than the others, depending on the value of other tunable parameters. We also
assess the performance of coarse-grained position measurement, showing that it
may be employed to realize nearly optimal estimation strategies.
