Intrinsic nonlinear Hall effect beyond Bloch geometry

Abstract: The theory of the intrinsic Hall effect, both linear and nonlinear, is rooted in a geometry which is defined in the Bloch-vector parameter space; the formal expressions are mostly derived from semiclassical concepts. When disorder and interaction are considered there is no Bloch vector to speak of; one needs a more general quantum geometry, defined in a different parameter space. Such higher-level geometrical formulation of the intrinsic Hall effect provides very compact expressions, which have the additional virtue -- in the Bloch special case -- of yielding the known results in a straightforward way: the logic is not concealed by the algebra.