Microwave quantum optics with Josephson traveling wave parametric amplifiers : generation of two-mode squeezed states

Josephson traveling wave parametric amplifiers have recently emerged as very promising platform for novel quantum optics experiments in microwave domain [1]. Engineering them at sub-wavelength scales can allow complete control over wave dispersion and non-linear interactions [2]. We will present observation of broadband two-mode squeezing generated by exciting a Josephson TWPA [3]. We will further discuss the hindrance posed by spurious processes in generation of these non-classical states. Engineering the dispersion of the TWPA can offer efficient solutions for suppressing these spurious processes. We will highlight our efforts towards understanding and mitigating the degradation of two-mode squeezing by higher order processes.

[1] M. Esposito et.al., Appl. Phys. Lett. 119, 120501 (2021)

[2] A. Ranadive et. al., Nat Comm 13, 1737 (2022)

[3] M. Esposito et.al., Phys. Rev. Lett. 128, 153603 (2022)