Reactive Hall response

The zero temperature Hall constant R-H, described by reactive (nondissipati ve) conductivities, is analyzed within linear response theory. It is found that in a certain limit RH is directly related to the density dependence of the Drude weight, implying a simple picture for the change of sign of char ge carriers in the vicinity of a Mott-Hubbard transition. This novel formul ation is applied to the calculation of R-H in quasi-one-dimensional and lad der prototype interacting electron systems.