@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{Turiansky2019,

title = {Dangling bonds in hexagonal boron nitride as single-photon emitters},

author = {M E Turiansky and A Alkauskas and L C Bassett and Van C G de Walle},

url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.127401},

doi = {10.1103},

issn = {1079-7114},

year  = {2019},

date = {2019-09-16},

journal = {Physical Review Letters},

volume = {123},

number = {12},

pages = {127401},

abstract = {Hexagonal boron nitride has been found to host color centers that exhibit single-photon emission, but the microscopic origin of these emitters is unknown. We propose boron dangling bonds as the likely source of the observed single-photon emission around 2 eV. An optical transition where an electron is excited from a doubly occupied boron dangling bond to a localized B pz state gives rise to a zero-phonon line of 2.06 eV and emission with a Huang-Rhys factor of 2.3. This transition is linearly polarized with the absorptive and emissive dipole aligned. Because of the energetic position of the states within the band gap, indirect excitation through the conduction band will occur for sufficiently large excitation energies, leading to the misalignment of the absorptive and emissive dipoles seen in experiment. Our calculations predict a singlet ground state and the existence of a metastable triplet state, in agreement with experiment.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Exarhos2017,

title = {Optical signatures of quantum emitters in suspended hexagonal boron nitride},

author = {A L Exarhos and D A Hopper and R R Grote and A Alkauskas and L C Bassett},

url = {https://pubs.acs.org/doi/abs/10.1021/acsnano.7b00665},

year  = {2017},

date = {2017-03-07},

journal = {ACS Nano},

volume = {11},

pages = {3328-3336},

abstract = {Hexagonal boron nitride (h-BN) is rapidly emerging as an attractive material for solid-state quantum engineering. Analogously to three-dimensional wide-band-gap semiconductors such as diamond, h-BN hosts isolated defects exhibiting visible fluorescence at room temperature, and the ability to position such quantum emitters within a two-dimensional material promises breakthrough advances in quantum sensing, photonics, and other quantum technologies. Critical to such applications is an understanding of the physics underlying h-BN’s quantum emission. We report the creation and characterization of visible single-photon sources in suspended, single-crystal, h-BN films. With substrate interactions eliminated, we study the spectral, temporal, and spatial characteristics of the defects’ optical emission. Theoretical analysis of the defects’ spectra reveals similarities in vibronic coupling to h-BN phonon modes despite widely varying fluorescence wavelengths, and a statistical analysis of the polarized emission from many emitters throughout the same single-crystal flake uncovers a weak correlation between the optical dipole orientations of some defects and h-BN’s primitive crystallographic axes, despite a clear misalignment for other dipoles. These measurements constrain possible defect models and, moreover, suggest that several classes of emitters can exist simultaneously throughout free-standing h-BN, whether they be different defects, different charge states of the same defect, or the result of strong local perturbations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bassett2014,

title = {Ultrafast optical control of orbital and spin dynamics in a solid-state defect},

author = {L C Bassett and F J Heremans and D J Christle and C G Yale and G Burkard and B B Buckley and D D Awschalom},

url = {https://science.sciencemag.org/content/345/6202/1333},

year  = {2014},

date = {2014-09-12},

journal = {Science},

volume = {345},

pages = {1333-1337},

abstract = {Atom-scale defects in semiconductors are promising building blocks for quantum devices, but our understanding of their material-dependent electronic structure, optical interactions, and dissipation mechanisms is lacking. Using picosecond resonant pulses of light, we study the coherent orbital and spin dynamics of a single nitrogen-vacancy center in diamond over time scales spanning six orders of magnitude. We develop a time-domain quantum tomography technique to precisely map the defect’s excited-state Hamiltonian and exploit the excited-state dynamics to control its ground-state spin with optical pulses alone. These techniques generalize to other optically addressable nanoscale spin systems and serve as powerful tools to characterize and control spin qubits for future applications in quantum technology.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@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 = {Condensed Matter, diamond NV center, nanodiamond assembly, Nanophotonics},

pubstate = {published},

tppubtype = {article}

}

@article{Turiansky2019,

title = {Dangling bonds in hexagonal boron nitride as single-photon emitters},

author = {M E Turiansky and A Alkauskas and L C Bassett and Van C G de Walle},

url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.127401},

doi = {10.1103},

issn = {1079-7114},

year  = {2019},

date = {2019-09-16},

journal = {Physical Review Letters},

volume = {123},

number = {12},

pages = {127401},

abstract = {Hexagonal boron nitride has been found to host color centers that exhibit single-photon emission, but the microscopic origin of these emitters is unknown. We propose boron dangling bonds as the likely source of the observed single-photon emission around 2 eV. An optical transition where an electron is excited from a doubly occupied boron dangling bond to a localized B pz state gives rise to a zero-phonon line of 2.06 eV and emission with a Huang-Rhys factor of 2.3. This transition is linearly polarized with the absorptive and emissive dipole aligned. Because of the energetic position of the states within the band gap, indirect excitation through the conduction band will occur for sufficiently large excitation energies, leading to the misalignment of the absorptive and emissive dipoles seen in experiment. Our calculations predict a singlet ground state and the existence of a metastable triplet state, in agreement with experiment.},

keywords = {2-dimensional systems, Condensed Matter, First-principles calculations, Optical absorption spectroscopy, Optical microcavities, optical sources, point defects, Quantum wells, Semiconductor compounds},

pubstate = {published},

tppubtype = {article}

}

@article{Exarhos2017,

title = {Optical signatures of quantum emitters in suspended hexagonal boron nitride},

author = {A L Exarhos and D A Hopper and R R Grote and A Alkauskas and L C Bassett},

url = {https://pubs.acs.org/doi/abs/10.1021/acsnano.7b00665},

year  = {2017},

date = {2017-03-07},

journal = {ACS Nano},

volume = {11},

pages = {3328-3336},

abstract = {Hexagonal boron nitride (h-BN) is rapidly emerging as an attractive material for solid-state quantum engineering. Analogously to three-dimensional wide-band-gap semiconductors such as diamond, h-BN hosts isolated defects exhibiting visible fluorescence at room temperature, and the ability to position such quantum emitters within a two-dimensional material promises breakthrough advances in quantum sensing, photonics, and other quantum technologies. Critical to such applications is an understanding of the physics underlying h-BN’s quantum emission. We report the creation and characterization of visible single-photon sources in suspended, single-crystal, h-BN films. With substrate interactions eliminated, we study the spectral, temporal, and spatial characteristics of the defects’ optical emission. Theoretical analysis of the defects’ spectra reveals similarities in vibronic coupling to h-BN phonon modes despite widely varying fluorescence wavelengths, and a statistical analysis of the polarized emission from many emitters throughout the same single-crystal flake uncovers a weak correlation between the optical dipole orientations of some defects and h-BN’s primitive crystallographic axes, despite a clear misalignment for other dipoles. These measurements constrain possible defect models and, moreover, suggest that several classes of emitters can exist simultaneously throughout free-standing h-BN, whether they be different defects, different charge states of the same defect, or the result of strong local perturbations.},

keywords = {2-dimensional systems, Condensed Matter, optical sources, point defects},

pubstate = {published},

tppubtype = {article}

}

@article{Bassett2014,

title = {Ultrafast optical control of orbital and spin dynamics in a solid-state defect},

author = {L C Bassett and F J Heremans and D J Christle and C G Yale and G Burkard and B B Buckley and D D Awschalom},

url = {https://science.sciencemag.org/content/345/6202/1333},

year  = {2014},

date = {2014-09-12},

journal = {Science},

volume = {345},

pages = {1333-1337},

abstract = {Atom-scale defects in semiconductors are promising building blocks for quantum devices, but our understanding of their material-dependent electronic structure, optical interactions, and dissipation mechanisms is lacking. Using picosecond resonant pulses of light, we study the coherent orbital and spin dynamics of a single nitrogen-vacancy center in diamond over time scales spanning six orders of magnitude. We develop a time-domain quantum tomography technique to precisely map the defect’s excited-state Hamiltonian and exploit the excited-state dynamics to control its ground-state spin with optical pulses alone. These techniques generalize to other optically addressable nanoscale spin systems and serve as powerful tools to characterize and control spin qubits for future applications in quantum technology.},

keywords = {Condensed Matter, point defects, spin readout},

pubstate = {published},

tppubtype = {article}

}