Microscopic origin and significance of the critical momentum scale

Determine the physical origin and microscopic significance of the critical momentum scale q_c governing the reconstruction and collapse of incoherent charge excitations in the strange-metal direction of MoOCl2.

Background

The measurements identify a thickness-independent critical momentum q_c ≈ 0.008 Å−1 at which the overdamped charge excitation in the strange-metal direction bends back, softens, and loses its collective character. The authors compare this observation with the phenomenological jamming model and a charge-conservation analysis, both of which anticipate a characteristic momentum but do not provide a microscopic theory of strange metallicity or account for the measured magnitude of q_c.

The invariance of q_c under substantial changes in Coulomb screening suggests that it is an intrinsic scale of the incoherent charge fluid rather than a screening-dependent quantity. Its physical origin and microscopic significance therefore remain unresolved.