A CMOS compatible platform for high impedance superconducting quantum circuits

TL;DR

This paper introduces a CMOS-compatible titanium nitride platform for superconducting quantum circuits, achieving high impedance and low microwave loss, advancing the development of next-generation quantum devices.

Contribution

It demonstrates a CMOS-compatible TiN platform with high kinetic inductance and impedance, providing insights into loss mechanisms for improved quantum circuit performance.

Findings

Large kinetic inductance (~240 pH/sq) achieved

High mode impedance (~4.2 kΩ) maintained

Microwave quality factor (~10^5) in single photon regime

Abstract

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 $\sim$3 nm, we measured large kinetic inductance LK $\sim$ 240 pH/sq, high mode impedance of $\sim$ 4.2 k$\Omega$ while maintaining microwave quality factor $\sim$ 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.