  The experimental characterization of quantum spin liquids poses significant
challenges due to the absence of long-range magnetic order, even at absolute
zero temperature. The identification of these states of matter often relies on
the analysis of their excitations. In this paper, we propose a method for
detecting the signatures of the fractionalized excitations in quantum spin
liquids using a tunneling spectroscopy setup. Inspired by the recent
development of the quantum twisting microscope, we consider a planar tunneling
junction, in which a candidate quantum spin liquid material is placed between
two graphene layers. By tuning the relative twist angle and voltage bias
between the leads, we can extract the dynamical spin structure factor of the
tunneling barrier with momentum and energy resolution. Our proposal presents a
promising tool for experimentally characterizing quantum spin liquids in
two-dimensional materials.
