High resolution, High contrast optical interface for defect qubits

Abstract

Point defects in crystals provide important building blocks for quantum applications. To initialize, control, and read-out their quantum states, an efficient optical interface for addressing defects with photons is required. However, conventional confocal fluorescence microscopy with high refractive index crystals has limited photon collection efficiency and spatial resolution. Here, we demonstrate high resolution, high contrast imaging for defects qubits using microsphere-assisted confocal microscopy. A microsphere provides an excellent optical interface for point defects with a magnified virtual image that improves spatial resolution up to ~$\lambda$/5 as well as an optical signal-to-noise ratio by four times. These features enable individual optical addressing of single photons and single spins of spatially-unresolved defects in conventional confocal microscopy with improved signal contrast. The combined optical tweezers show the possibility of positioning or scanning the microspheres for deterministic coupling and wide-field imaging of defects. The approach does not require any complicated fabrication and additional optical system but uses simple micro-optics off-the-shelf. From these distinctive advantages of the microspheres, our approach can provide an efficient way for imaging and addressing closely-spaced defects with higher resolution and sensitivity.

arXiv comment20 pages, 5 figures

References in corpus (28)

• Sensing electric fields using single diamond spins
• The optical microscopy with virtual image breaks a record: 50-nm resolution imaging is demonstrated
• A Diamond Nanowire Single Photon Antenna
• High-fidelity projective readout of a solid-state spin quantum register
• Probing condensed matter physics with magnetometry based on nitrogen-vacancy centres in diamond
• Scalable quantum register based on coupled electron spins in a room temperature solid
• A 10-qubit solid-state spin register with quantum memory up to one minute
• Coupling of Nitrogen-Vacancy Centers to Photonic Crystal Cavities in Monocrystalline Diamond
• Sub-millihertz magnetic spectroscopy with a nanoscale quantum sensor
• Photon-mediated interactions between quantum emitters in a diamond nanocavity
• Strongly enhanced photon collection from diamond defect centres under micro-fabricated integrated solid immersion lenses
• Quantum imaging of current flow in graphene
• Three megahertz photon collection rate from an NV center with millisecond spin coherence
• Coupling of a single NV-center in diamond to a fiber-based microcavity
• Deterministic enhancement of coherent photon generation from a nitrogen-vacancy center in ultrapure diamond
• Superradiant Hybrid Quantum Devices
• Locomotion of microspheres for super-resolution imaging
• Observation of room-temperature spontaneous superradiance from single diamond nanocrystals
• Fourier Magnetic Imaging with Nanoscale Resolution and Compressed Sensing Speed-up using Electronic Spins in Diamond
• Super-radiant emission from quantum dots in a nanophotonic waveguide
• Integrated Diamond Optics for Single Photon Detection
• Microscopic diamond Solid-Immersion-Lenses fabricated around single defect ceneters by focussed ion beam milling
• Efficient Extraction of Light from a Nitrogen-Vacancy Center in a Diamond Parabolic Reflector
• Enhanced metrology using preferential orientation of nitrogen-vacancy centers in diamond
• Nanopositioning of a diamond nanocrystal containing a single NV defect center
• Inverse-designed photon extractors for optically addressable defect qubits
• Simultaneous Wide-field Imaging of Phase and Magnitude of AC Magnetic Signal Using Diamond Quantum Magnetometry
• Super-resolution imaging and microscopy by dielectric particle-lenses