Pressure-enhanced fractional Chern insulators along a magic line in moiré transition metal dichalcogenides

We show that pressure applied to twisted WSe2 can enhance the many-body gap and region of stability of a fractional Chern insulator at filling & nu; = 1/3. Our results are based on exact diagonalization of a continuum model, whose pressure dependence is obtained through ab initio methods. We interpret our results in terms of a magic line in the pressure-vs-twist angle phase diagram: along the magic line, the bandwidth of the topmost moire valence band is minimized while simultaneously its quantum geometry resembles that of an ideal Chern band. We expect our results to generalize to other twisted transition metal dichalcogenide homobilayers.