Crossed Luttinger liquid hidden in a quasi-two-dimensional material

Although the concept of Luttinger liquid (LL) that describes a one-dimensional (1D) interacting fermion system collapses in higher dimensions, it has been proposed to be closely related many mysteries including normal state cuprate superconductor, unconventional metal, and quantum criticality. Therefore, generalization LL model dimensions attracted substantial research attention. Here we systematically investigate electronic structure quasi-2D compound {\eta}-Mo4O11 using high-resolution angle-resolved photoemission spectroscopy ab-initio calculation. Remarkably, reveal prototypical behavior originating from crossing quasi-1D chain arrays hidden crystal structure. Our results suggest materializes long sought-after crossed phase, where orthogonal orbital components significantly reduce coupling between intersecting chains therefore maintain essential properties LL. finding not only presents realization 2D LL, but also provides new angle understand non-Fermi behaviors other 3D materials.