Thick braneworld in f(Q,T) gravity

In this work, we study a codimension-one thick brane in modified symmetric teleparallel gravity for the specific additive ansatz f(Q,T) = Q + k₁ Qⁿ + k₂T f ( Q , T ) = Q + k 1 Q n + k 2 T . Using two physically motivated warp factor, we construct the full brane system, derive background solutions, and analyze how nonmetricity corrections and the matter-trace coupling modify brane internal structure and graviton localization. For both warp profiles, we obtain the corresponding Schrödinger-like equation for tensor perturbations, identify conditions for volcano and multi-well effective potentials, and determine when a localized zero mode arises. We discuss the physical implications of our results, such as possible short-range corrections to Newton’s law and resonant Kaluza–Klein modes, and outline observational prospects and directions for future work.