At very low temperatures near the absolute zero, most of the matters will be freeze, hence the electrons become highly ordered. Quantum spin liquid is a novel phenomenon in which the electrons are entangled, but they remain fluctuating down to 0 K. A few quantum spin liquid materials have been reported and they have potential applications in data storage and memory. In this talk, I will present a new material, barium niobium iridium oxide-Ba4NbIr3O12, which can host a quantum spin liquid state, probed by magnetic susceptibility and heat capacity measurements. A comparison will be made to other related materials in the family.