Possible Sliding Regimes in Twisted Bilayer WTe2

Inspired by the observation of increasingly one-dimensional (1D) behavior with decreasing temperature in small-angle twisted bilayers of ${\mathrm{WTe}}_{2}$ (${\mathrm{tWTe}}_{2}$), we theoretically explore the exotic sliding regimes that could be realized in ${\mathrm{tWTe}}_{2}$. At zero displacement field, while hole-doped ${\mathrm{tWTe}}_{2}$ can be thought of as an array of weakly coupled conventional two-flavor 1D electron gases (1DEGs), the electron-doped regime is equivalent to coupled four-flavor 1DEGs, due to the presence of an additional ``valley'' degree of freedom. In the decoupled limit, the electron-doped system can thus realize phases with a range of interesting ordering tendencies, including $4{k}_{F}$ charge-density-wave and charge-$4e$ superconductivity. Dimensional crossovers and cross-wire transport due to interwire couplings of various kinds are also discussed. We find that a sliding Luther-Emery liquid with small interwire couplings is probably most consistent with current experiments on hole-doped ${\mathrm{tWTe}}_{2}$.