Phys.org June 18, 2024
The lack of nonlinearity in photonics has led to encoded measurement-based quantum computing, which relies on linear operations but requires access to resourceful (’nonlinear’) quantum states. In contrast, superconducting microwave circuits offer engineerable nonlinearities but suffer from static Kerr nonlinearity. An international team of researchers (Sweden, Germany) demonstrated universal control of a bosonic mode composed of a superconducting nonlinear asymmetric inductive element (SNAIL) resonator, enabled by native nonlinearities in the SNAIL element. They suppressed static nonlinearities and dynamically activated nonlinearities up to third order by fast flux pulses. They experimentally realized a universal set of generalized squeezing operations, as well as the cubic phase gate, and exploited them to deterministically prepare a cubic phase state in 60 ns. According to the researchers their results initiated the experimental field of polynomial quantum computing, in the continuous-variables notion originally introduced by Lloyd and Braunstein… read more. Open Access TECHNICAL ARTICLEÂ
Experimental demonstration of the cubic gate by generation of a cubic phase state in 60 ns. Credit: Nature Communications volume 15, Article number: 2512 (2024)