Three-wave mixing traveling-wave parametric amplifier with periodic variation of the circuit parameters

We report the implementation of a near-quantum-limited, traveling-wave parametric amplifier that uses three-wave mixing (3WM). To favor amplification by 3WM, we use the superconducting nonlinear asymmetric inductive element (SNAIL) loops, biased with a dc magnetic flux. In addition, we equip the device with dispersion engineering features to create a stop-band at the second harmonic of the pump and suppress the propagation of the higher harmonics that otherwise degrade the amplification. With a chain of 440 SNAILs, the amplifier provides up to 20 dB gain and a 3-dB bandwidth of 1 GHz. The added noise by the amplifier is found to be less than one photon.

Automated summary

We present the implementation of a traveling-wave parametric amplifier using three-wave mixing (3WM) that achieves near-quantum-limited performance. By utilizing superconducting nonlinear asymmetric inductive element (SNAIL) loops biased with a dc magnetic flux, we enhance the amplification by 3WM. Furthermore, we incorporate dispersion engineering features to create a stop-band at the pump's second harmonic and suppress the higher harmonics, resulting in improved amplification. With a chain of 440 SNAILs, the amplifier achieves up to 20 dB gain and a 3-dB bandwidth of 1 GHz. The added noise by the amplifier is found to be less than one photon.