Fermi surface reconstruction and anisotropic linear magnetoresistance in the charge density wave topological semimetal TaTe₄

Understanding the interplay between topology and correlated electron states is central to the study of quantum materials. TaTe₄ is a quasi-one-dimensional charge density wave (CDW) compound predicted to host topological phases, making it a model platform to explore this interplay. Here, we combine high-field magnetotransport measurements with density functional theory calculations to provide a comprehensive mapping of the Fermi surface (FS) of TaTe₄ in its CDW phase. Using multiple current-field geometries, we resolve the four largest of six pockets of the FS predicted by theory and find no evidence of non-CDW bands, highlighting the full reconstruction of the FS in the bulk. We identify a previously unobserved quasi-cylindrical pocket and uncover a large size orbit consistent with magnetic breakdown between reconstructed FS sheets, from which we estimate a CDW gap of ~ 0.29 eV. Moreover, we observe a robust linear magnetoresistance that persists across all field directions when current flows perpendicular to the 1D chains along which the CDW is formed, with a distinct high-field linear regime emerging when field is along the chains. These findings establish TaTe₄ as a prototypical material to study the coexistence of correlation-driven reconstruction and topological electronic states.