@article{Shulevitz2021,
title = {Template-Assisted Self Assembly of Fluorescent Nanodiamonds for Scalable Quantum Technologies},
author = {Henry J. Shulevitz and Tzu-Yung Huang and Jun Xu and Steven Neuhaus and Raj N. Patel and Lee C. Bassett, Cherie R. Kagan},
url = {https://arxiv.org/abs/2111.14921},
doi = {10.1021/acsnano.1c09839},
year = {2022},
date = {2022-01-13},
journal = {ACS Nano},
volume = {16},
number = {2},
pages = {1847–1856},
abstract = {Milled nanodiamonds containing nitrogen-vacancy (NV) centers provide an excellent platform for sensing applications as they are optically robust, have nanoscale quantum sensitivity, and form colloidal dispersions which enable bottom-up assembly techniques for device integration. However, variations in their size, shape, and surface chemistry limit the ability to position individual nanodiamonds and statistically study properties that affect their optical and quantum characteristics. Here, we present a scalable strategy to form ordered arrays of nanodiamonds using capillary-driven, template-assisted self assembly. This method enables the precise spatial arrangement of isolated nanodiamonds with diameters below 50 nm across millimeter-scale areas. Measurements of over 200 assembled nanodiamonds yield a statistical understanding of their structural, optical, and quantum properties. The NV centers' spin and charge properties are uncorrelated with nanodiamond size, but rather are consistent with heterogeneity in their nanoscale environment. This flexible assembly method, together with improved understanding of the material, will enable the integration of nanodiamonds into future quantum photonic and electronic devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Fishman2021,
title = {Photon emission correlation spectroscopy as an analytical tool for quantum defects},
author = {Rebecca E. K. Fishman and Raj N. Patel and David A. Hopper and Tzu-Yung Huang and Lee C. Bassett},
url = {https://arxiv.org/abs/2111.01252},
year = {2021},
date = {2021-11-04},
abstract = {Photon emission correlation spectroscopy has a long history in the study of atoms, molecules, and, more recently, solid-state quantum defects. In solid-state systems, its most common use is as an indicator of single-photon emission, a key property for quantum technology. However, photon correlation data can provide a wealth of information about quantum emitters beyond their single-photon purity−information that can reveal details about an emitter's electronic structure and optical dynamics that are hidden by other spectroscopy techniques. We present a standardized framework for using photon emission correlation spectroscopy to study quantum emitters, including discussion of theory, data acquisition, analysis, and interpretation. We highlight nuances and best practices regarding the commonly used g(2)(τ=0)<0.5 test for single-photon emission. Finally, we illustrate how this experimental technique can be paired with optical dynamics simulations to formulate an electronic model for unknown quantum emitters, enabling the design of quantum control protocols and assessment of their suitability for quantum information science applications.},
keywords = {},
pubstate = {forthcoming},
tppubtype = {article}
}

@article{Hopper2019,
title = {Real-Time Charge Initialization of Diamond Nitrogen-Vacancy Centers for Enhanced Spin Readout},
author = {D A Hopper and J D Lauigan and T -Y Huang and L C Bassett},
url = {https://arxiv.org/abs/1907.08741
https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.13.024016
https://medium.com/penn-engineering/penn-engineers-ensure-quantum-experiments-get-off-to-the-right-start-bbe6f3382cb},
year = {2020},
date = {2020-02-07},
journal = {Phys. Rev. Applied},
volume = {13},
pages = {024016},
abstract = {Selected as an Editor's Suggestion.

A common impediment to qubit performance is imperfect state initialization. In the case of the diamond nitrogen-vacancy (NV) center, the initialization fidelity is limited by fluctuations in the defect's charge state during optical pumping. Here, we use real-time control to deterministically initialize the NV center's charge state at room temperature. We demonstrate a maximum charge initialization fidelity of 99.4±0.1% and present a quantitative model of the initialization process that allows for systems-level optimization of the spin-readout signal-to-noise ratio. Even accounting for the overhead associated with the initialization sequence, increasing the charge initialization fidelity from the steady-state value of 75% near to unity allows for a factor-of-two speedup in experiments while maintaining the same signal-to-noise-ratio. In combination with high-fidelity readout based on spin-to-charge conversion, real-time initialization enables a factor-of-20 speedup over traditional methods, resulting in an ac magnetic sensitivity of 1.3 nT/Hz1/2 for our single NV-center spin. The real-time control method is immediately beneficial for quantum sensing applications with NV centers as well as probing charge-dependent physics, and it will facilitate protocols for quantum feedback control over multi-qubit systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Huang2019,
title = {Imaging a nitrogen-vacancy center with a diamond immersion metalens},
author = {T -Y Huang and R R Grote and S A Mann and D A Hopper and A L Exarhos and G G Lopez and A R Klein and E C Garnett and L C Bassett},
url = {https://www.nature.com/articles/s41467-019-10238-5
https://medium.com/penn-engineering/penn-engineers-design-nanostructured-diamond-metalens-for-compact-quantum-technologies-271adddf69ba},
year = {2019},
date = {2019-06-03},
journal = {Nature Communications},
volume = {10},
number = {2392},
abstract = {Quantum emitters such as the diamond nitrogen-vacancy (NV) center are the basis for a wide range of quantum technologies. However, refraction and reflections at material interfaces impede photon collection, and the emitters’ atomic scale necessitates the use of free space optical measurement setups that prevent packaging of quantum devices. To overcome these limitations, we design and fabricate a metasurface composed of nanoscale diamond pillars that acts as an immersion lens to collect and collimate the emission of an individual NV center. The metalens exhibits a numerical aperture greater than 1.0, enabling efficient fiber-coupling of quantum emitters. This flexible design will lead to the miniaturization of quantum devices in a wide range of host materials and the development of metasurfaces that shape single-photon emission for coupling to optical cavities or route photons based on their quantum state.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}