Confinement-induced nonlocality and Casimir force in transdimensional plasmonic systems

We apply a confinement-induced nonlocal electromagnetic response model [1,2] to generalize the Lifshitz theory of the long-range Casimir force for in-plane isotropic and anisotropic ultrathin transdimensional material slabs [3]. In the former case, we show that the confinement-induced nonlocality not only weakens the attraction of ultrathin slabs but also changes the distance dependence of the material-dependent correction to the Casimir force to go as inverse square root of distance contrary to the inverse distance dependence of that of the local Lifshitz force. In the latter case, we use closely packed array of parallel aligned single-wall carbon nanotubes in a dielectric layer of finite thickness to demonstrate strong orientational anisotropy and crossover behavior for the interslab attractive force in addition to its reduction with decreasing slab thickness. We give physical insight as to why such a pair of ultrathin slabs prefers to stick together in the perpendicularly oriented manner, rather than in the parallel relative orientation as one would customarily expect. – [1] I.V.Bondarev, H.Mousavi, & V.M.Shalaev, PRR 2, 013070 (2020); [2] S.-A.Biehs & I.V.Bondarev, AOM 11, 2202712 (2023); [3] I.V.Bondarev, et al., PCCP, doi: 10.1039/D3CP03706A (2023).