Strong field physics enabled by a 100 PW laser

A 100 PW laser can support focal intensities beyond 10$^{\mathrm{23}}$W/cm$^{\mathrm{2}}$, which will drive the interaction into the strong relativistic regime and create QED-featured plasma. In the former, charged particles can be accelerated to the unprecedented GeV to tens-of-GeV level via laser-driven wakefield acceleration. The concept of laser-driven table-tap accelerators can be significantly advanced. Further, interaction in the near-QED regime will exhibit exotic new effects such as gamma photons emission, radiation-reaction effect and QED cascade. A most exciting prospect is combining a 100 PW laser with a hard X-ray free-electron laser (XFEL) facility. It will lead the chasing on the discovering vacuum birefringence-a prominent strong field QED effect of vacuum. The proposed scientific activities and experimental design are introduced for a 100 PW laser system.