Loss mechanisms in TiN high impedance superconducting microwave circuits

Overview & Synopsis

Aluminium based platforms have allowed to reach major milestones for superconducting quantum circuits. For the next generation of devices, materials that are able to maintain low microwave losses while providing new functionalities, such as large kinetic inductance or compatibility with CMOS platform are sought for. Here we report on a combined direct current (DC) and microwave investigation of titanium nitride lms of dierent thicknesses grown using CMOS compatible methods. For microwave resonators made of TiN lm of thickness ∼3 nm, we measured large kinetic inductance LK ∼ 240 pH/sq, high mode impedance of ∼ 4.2 kΩ while maintaining microwave quality factor ∼ 10^5 in the single photon limit. We present an in-depth study of the microwave loss mechanisms in these devices that indicates the importance of quasiparticles and provide insights for further improvement.