Displacement of Propagating Squeezed Microwave States

Phys Rev Lett. 2016 Jul 8;117(2):020502. doi: 10.1103/PhysRevLett.117.020502. Epub 2016 Jul 7.

Abstract

Displacement of propagating quantum states of light is a fundamental operation for quantum communication. It enables fundamental studies on macroscopic quantum coherence and plays an important role in quantum teleportation protocols with continuous variables. In our experiments, we have successfully implemented this operation for propagating squeezed microwave states. We demonstrate that, even for strong displacement amplitudes, there is no degradation of the squeezing level in the reconstructed quantum states. Furthermore, we confirm that path entanglement generated by using displaced squeezed states remains constant over a wide range of the displacement power.