Higher-order squeezing and entanglement of harmonic oscillators in superconducting circuits
Fei Wang, Wei Nie, C. H. Oh · Journal of the Optical Society of America B · 2016
We show that it is possible to obtain higher-order squeezing and entanglement between a pair of harmonic oscillators coupled to a single Δ-type artificial atom, which is realized because of the broken mirror symmetry of the effective potential in the superconducting circuits. Under the three-photon resonance and adiabatic conditions, the system can act as a coherence-controlled atomic reservoir, resulting in the generation of higher-order nonclassicality at steady state. The stable higher-order nonclassical correlations of the two harmonic oscillators in this solid-state device may find potential applications in quantum communications.