Photons paired with phonons

Tingting Ma, Yu‐qiang Liu, Chang‐shui Yu

The most important difference between ultrastrong and non-ultrastrong coupling regimes is that the ground state contains excitations. We consider a qubit-plasmon-phonon ultrastrong coupling (USC) system with a three-level atom coupled to the photon and phonon via its upper two energy levels and show that spontaneous emission of the atom from its intermediate to its ground state produces photon and phonon pairs. It is shown that the current system can produce a strong photon/phonon stream and the atom-phonon coupling plays the active role, which ensures the experimental detection. The emission spectrum and various high-order correlation functions confirm the generation of the pairs of photons and phonons. Our study has important implications for future research on virtual photon and phonon pairs creation in the ground state of the USC regime.

Vivishek Sudhir

Günter Nimtz

Xun‐Wei Xu, Hai-Quan Shi, Jie‐Qiao Liao +1 more

Antibunching and entanglement play important roles in quantum information processing as antibunching is an essential ingredient for the production of single photons (phonons) and entanglement is a crucial resource for quantum communication and metrology. In this paper, we propose a atom-photon-phonon (tripartite) interaction in a hybrid cavity-atom-mechanics system, and show that both photon and phonon antibunching can be observed simultaneously under the resonant atomic driving. More importantly, the generated single photons and phonons are strongly correlated and entangled with each other, i.e., single entangled photon-phonon pairs are generated via the atom-photon-phonon interaction. The generation of single entangled photon-phonon pairs is the first step to implement entanglement-based quantum state transfer, which is essential for connecting mechanical and optical systems to build hybrid quantum networks.

N. S. Shiren

Zhenshan S. Yang, Xia Zhang, Minghong Wang +1 more

We show that an entangled traveling photon-phonon pair can be generated in a resonator-waveguide structure via optomechanical interaction. We employ the ``backward Heisenberg picture'' approach to write an analytic expression for the output quantum state, from which the generation efficiency and the entanglement of the photon-phonon pair are calculated. We find that the photon-phonon entanglement can be manipulated by adjusting the spectral width of the input pulse.