A transverse magnetic field is used to scan the diagonal and off-diagonal susceptibility of the uniaxial quantum magnet, $text{LiHo}_{0.045}text{Y}_{0.955}text{F}_4$. Clusters of strongly-coupled spins act as the primary source for the response funct
ions, which result from a field-induced quantum projection of the system into a classically forbidden (meaning non-Ising) regime. Calculations based on spin pairs reproduce only some features of the data and fail to predict the measured off-diagonal response, providing evidence of a multi-spin collective state.
