Hybrid Quantum Photonics Based on Artificial Atoms Placed Inside One Hole of a Photonic Crystal Cavity

Abstract

Spin-based, quantum-photonics promise to realize distributed quantum computing and quantum networks. The performance depends on an efficient entanglement distribution where cavity quantum electrodynamics could boost the efficiency. The central challenge is the development of compact devices with large spin-photon coupling rates and a high operation bandwidth. Photonic crystal cavities comprise strong field confinement but require highly accurate positioning of atomic systems in mode field maxima. Negatively charged silicon-vacancy centers in diamond emerged as promising atom-like systems. Spectral stability and access to long-lived, nuclear-spin memories enabled elementary demonstrations of quantum network nodes, including memory-enhanced quantum communication. In a hybrid approach, we deterministically place SiV-containing nanodiamonds inside one hole of one-dimensional, freestanding, Si3N4-based photonic crystal cavities and coherently couple individual optical transitions to cavity modes. We optimize light–matter coupling utilizing two-mode composition, waveguiding, Purcell-enhancement, and cavity-resonance tuning. The resulting photon flux increases by 14 compared to free space. Corresponding lifetime-shortening below 460 ps puts potential operation bandwidth beyond GHz rates.

Hybrid Quantum Nanophotonics: Interfacing Color Center in Nanodiamonds with Si3N4-Photonics

“…Thus, both pump and read-out ports are on-chip and are accessible for additional on-chip photonic technology. demonstrated in the works [73,97,98]. We explore the LDOS enhancement spatial map and determine an optimized position for the emitter in the cavity region in order to obtain a maximum enhancement of the emission coupled into certain resonance modes.…”

“…The high spatial precision of the AFM-based nanomanipulation enables an extremely high accuracy in assembling hybrid devices. As a recent example, individual NDs hosting SiV centers were positioned inside the hole of a PhC cavity [98], as summarized in Fig. 20 d).…”

“…Therefore, a very precise nanomanipulation is required. In the work [98] the precision of the QPP was pushed to an extreme by placing a ND, which contains SiV centers, inside the hole of a PhC cavity by using the AFM-based pick and place technique. As a result, the corresponding coupling strength got another boost from an improved Purcell-enhancement and, at the same time, from waveguiding effects.…”

Diamond Integrated Quantum Photonics: A Review

“…Coupling between color centers in diamond and photonic resonators has been demonstrated on various different platforms [151], including, but not limited to, photonic crystal cavities [186], [196], [310]- [312], nanobeam cavities [41], [42], [240], [241], [313]- [315], waveguides [229], [316], [317], microrings [230], [318], [319], hybrid optical devices [320]- [325] and open microcavities [122], [326]- [331].…”

On-chip single-photon subtraction by individual silicon vacancy centers in a laser-written diamond waveguide

“…Another approach is hybrid quantum photonics, which offers the advantage of separate optimization of the photonics and the quantum emitter. However, the hybrid approach relies on elaborate manual functional-ization [17][18][19].…”