Description
Superconducting quantum technologies have emerged as a leading platform for quantum computing and quantum sensing over the past three decades. A key enabling component in these systems is the quantum-limited amplifier (QLA), which is essential for high-fidelity qubit readout and has also found important applications in areas such as dark matter detection [1]. State-of-the-art QLAs are predominantly based on Josephson junctions, offering excellent noise performance but suffering from low saturation power, and incompatibility with elevated temperatures and magnetic fields [2]. These limitations present a significant challenge to the use of QLAs in applications beyond quantum computing.
In this talk, I will present our progress towards Josephson-junction-free quantum amplifiers based on the intrinsic kinetic inductance nonlinearity of NbTiN superconducting thin films [3]. In particular, I will discuss the development of wafer-scale engineered kinetic-inductance travelling-wave parametric amplifiers (KITWPAs) using a multilayer architecture in which the signal and ground planes are separated by a dielectric layer. This design significantly reduces the likelihood of fabrication-induced defects, providing a robust and scalable platform for KITWPA implementation. We have established a complete end-to-end fabrication process for these multilayer devices and have experimentally demonstrated gains of up to 16 dB over more than 2 GHz of bandwidth.
These results demonstrate a promising route towards scalable kinetic-inductance parametric amplifiers offering broadband gain, high dynamic range, and compatibility with higher magnetic fields and operating temperatures, addressing a key constraint in the broader deployment of superconducting QLAs.
[1] J. Aumentado, IEEE Microwave Magazine 21(8), 45–59 (2020)
[2] C. Macklin et al., Science 350, 307–310 (2015)
[3] B. H. Eom et al., Nature Physics 8, 623–627 (2012).
| I am the presenting author | Yes |
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