QIQBセミナー: Strong coupling of a single ion to an optical cavity

講師: 高橋優樹 東京大学 特任助教
分野: イオントラップ、共振器電磁力学 

Title:  Strong coupling of a single ion to an optical cavity 
Due to their outstanding properties such as stationary trapping, long coherence times and the ability of high-fidelity quantum control, trapped ions are a leading physical system for optical atomic clocks, quantum metrology, and quantum simulation and computation. 

The setting of cavity quantum electrodynamics (QED) brings about exciting possibilities to connect such individual quantum devices by providing efficient reversible quantum interfaces with optical photons. For example this enables the distributed architecture using photonic quantum networks for large scale quantum information processing using trapped ions. 

In many applications of cavity QED, the coherent atom-photon interaction rate needs to exceed the decoherence rates of the system. This so-called strong coupling regime has been attained in many physical systems including neutral atoms, solid state systems and an ensemble of trapped ions. However, it has thus far remained elusive for single trapped ions. The main challenge in ion-cavity systems is to achieve small enough mode volume of the cavity without disturbing the trapping field when incorporating dielectric cavity mirrors near the trapping region. Based on the ion trap with an integrated fiber Fabry-Perot cavity that we developed, we have demonstrated the coupling of a single ion to an optical cavity with a coupling strength exceeding both atomic and cavity decay rates, reaching the strong coupling regime for the first time with a single ion. 

In this presentation, I will present the latest results from the experiment that achieved strong coupling with a single ion. Furthermore I discuss the future plans for applications of our strong coupling ion-cavity system, including optical interconnection between individual ion traps.