A new tetragonal superconductor withTc $=$ 3.5K

We report the discovery of a new tetragonal superconductor at 3.5 K. Tetragonal structure has been found as a frequent platform for superconductivity, like cuprate, Iron pnictide materials. Very similar to these families, our semiconducting parent compound exhibits a charge density wave or spin density wave transition at the room temperature, according to the transport and magnetic measurements. With chemical doping, the CDW/SDW transition has been suppressed, and bulk superconductivity emerges up to 3.5K. The chemical doping also leads to a structure transition in this family.