Phonon-number-resolving detection of multiple local phonon modes in trapped ions

Yoshikazu MARUHASHI

Ryutaro Ohira, Shota Kume, Kyoichi Takayama +2 more

Mahmoud Abdel‐Aty, Arthur R. McGurn

Ryutaro Ohira, Takashi Mukaiyama, Kenji Toyoda

We propose and demonstrate phonon-number-resolving detection of the multiple local phonon modes in a trapped-ion chain. To mitigate the effect of phonon hopping during the detection process, the probability amplitude of each local phonon mode is mapped to the auxiliary long-lived motional ground states. Sequential state-dependent fluorescence detection is then performed. In the experiment, we have successfully observed the time evolution of two local phonon modes in two ions, including the phonon-number correlation between the two modes.

David B. Hume, Till Rosenband, David J. Wineland

Ryutaro Ohira, Shota Kume, Kyoichi Takayama +3 more

Driving an ion at a motional sideband transition induces the Jaynes--Cummings (JC) interaction. This JC interaction creates an anharmonic ladder of JC eigenstates, resulting in the suppression of phonon hopping due to energy conservation. Here, we report the confinement of multiple local phonons to a single ion site using this nonlinear quantum effect. By using phonon-number-resolving detection, we observe the dynamics of multiple phonons in an ion chain. In addition to simply confining local phonons, by turning the JC interaction on and off dynamically, we can confine a single local phonon to a single ion site and subsequently retrieve it out of the site. Our work establishes a key technological component for quantum simulation with multiple bosonic particles, which can simulate classically intractable problems.