  The influence of a perpendicular magnetic field on the binding energy and
structural properties of excitons, trions, and biexcitons in monolayers of
semiconducting transition metal dichalcogenides (TMDs) is investigated. The
stochastic variational method (SVM) with a correlated Gaussian basis is used to
calculate the different properties of these few-particle systems. In addition,
we present a simplified variational approach which supports the SVM results for
excitons as a function of magnetic field. The exciton diamagnetic shift is
compared with recent experimental results and we extend this concept to trions
and biexcitons. The effect of a local potential fluctuation, which we model by
a circular potential well, on the binding energy of trions and biexcitons is
investigated and found to significantly increase the binding of those excitonic
complexes.
