The relation between enhanced superconductivity in monolayer FeSe grown on SrTiO3 and the large nematicity in multilayer FeSe on SrTiO3 remains not well understood. Here, the authors observe a long-range smectic phase in bilayer FeSe films but vanishes in monolayer FeSe, providing a new instability to help enhance the superconductivity.
- Yonghao Yuan
- Xuemin Fan
- Wei Li
