Fabrication of Sawfish photonic crystal cavities in bulk diamond

Abstract

Color centers in diamond are quantum systems with optically active spin-states that show long coherence times and are therefore a promising candidate for the development of efficient spin-photon interfaces. However, only a small portion of the emitted photons is generated by the coherent optical transition of the zero-phonon line (ZPL), which limits the overall performance of the system. Embedding these emitters in photonic crystal cavities improves the coupling to the ZPL photons and increases their emission rate. Here, we demonstrate the fabrication process of "Sawfish" cavities, a design recently proposed that has the experimentally-realistic potential to simultaneously enhance the emission rate by a factor of 46 and couple photons into a single-mode fiber with an efficiency of 88%. The presented process allows for the fabrication of fully suspended devices with a total length of 20.5 $\mu$m and features size as small as 40 nm. The optical characterization shows fundamental mode resonances that follow the behavior expected from the corresponding design parameters and quality (Q) factors as high as 3825. Finally, we investigate the effects of nanofabrication on the devices and show that, despite a noticeable erosion of the fine features, the measured cavity resonances deviate by only 0.9 (1.2)% from the corresponding simulated values. This proves that the Sawfish design is robust against fabrication imperfections, which makes it an attractive choice for the development of quantum photonic networks.

7 pages, 9 figures

References in corpus (13)

• Realization of a multi-node quantum network of remote solid-state qubits
• Experimental demonstration of memory-enhanced quantum communication
• Coherent spin control of a nanocavity-enhanced qubit in diamond
• Spectroscopic Investigations of Negatively Charged Tin-Vacancy Centres in Diamond
• A Quantum Photonic Interface for Tin-Vacancy Centers in Diamond
• Coupling of a Single Tin-vacancy Center to a Photonic Crystal Cavity in Diamond
• Fabrication of Triangular Nanobeam Waveguide Networks in Bulk diamond Using Single-Crystal Silicon Hard Masks
• 'Sawfish' Photonic Crystal Cavity for Near-Unity Emitter-to-Fiber Interfacing in Quantum Network Applications
• Coherent microwave, optical, and mechanical quantum control of spin qubits in diamond
• Efficient Microwave Spin Control of Negatively Charged Group-IV Color Centers in Diamond
• SUPER and femtosecond spin-conserving coherent excitation of a tin-vacancy color center in diamond
• Deterministic Creation of Large Photonic Multipartite Entangled States with Group-IV Color Centers in Diamond
• Optical probing of phononic properties of a tin-vacancy color center in diamond

Cited by in corpus (3)

• Coherent microwave, optical, and mechanical quantum control of spin qubits in diamond
• Waveguide-integrated colour centres in silicon carbide with broadband photonic crystal reflectors for efficient readout
• Software Framework for Optically Accessible Quantum Memory Using Group-IV Color Centers in Diamond