Lead-Related Quantum Emitters in Diamond

Abstract

We report on quantum emission from Pb-related color centers in diamond following ion implantation and high-temperature vacuum annealing. First-principles calculations predict a negatively charged Pb-vacancy (PbV) center in a split-vacancy configuration, with a zero-phonon transition around 2.4 eV. Cryogenic photoluminescence measurements performed on emitters in nanofabricated pillars reveal several transitions, including a prominent doublet near 520 nm. The splitting of this doublet, 5.7 THz, exceeds that reported for other group-IV centers. These observations are consistent with the PbV center, which is expected to have a combination of narrow optical transitions and stable spin states, making it a promising system for quantum network nodes.

Versatile direct-writing of dopants in a solid state host through recoil implantation

“…For instance, the SiV ZPL is almost always at the same wavelength ≅738 m, while the PbV and SnV ZPL vary over several nm. Furthermore, additional spectral lines (tentatively attributed to intermediate defect states) appear to a greater extent and with higher frequency for heavier implants, as discussed in the Supplementary Note 8 14,35,37 . Whilst some of these characteristics can be attributed to an increase in strain associated with dopant size, these results warrant further investigation, in particular towards optimisation of the annealing process 35,38 .…”

“…Of particular interest is the generation of optically addressable qubits such as colour centres in diamond, silicon carbide (SiC) or yttrium orthovanadate (YVO 4 ) which are considered prime candidates for scalable quantum technologies [5][6][7][8] . Examples include the nitrogen vacancy (NV) centre 9 and more recently the group IV elements [10][11][12][13][14][15][16] in diamond that exhibit excellent optical and coherence properties suitable for quantum circuitry [17][18][19] .…”

Quantum Materials with Atomic Precision: Artificial Atoms in Solids: Ab Initio Design, Control, and Integration of Single Photon Emitters in Artificial Quantum Materials

“…[2] Copyright 2015, Nature Publishing Group, Figure reproduced with permission. [3] Copyright 2019, American Physical Society, Figure reproduced with permission. [4] Copyright 2018, American Physical Society, Figure reproduced with permission.…”

“…So far, however, because of a lack of experimental and theoretical tools, the search for new emitters which overcome these obstacles is largely based on intuition-guided "trial and error". Looking forward, the field would strongly benefit from first-principles prediction [3,22,23,37] and design of emitters with desired quantum properties, including a large Debye-Waller factor, long coherence time, high emission efficiency, single-photon purity, as well as spectral stability. Rational materials design using first principles methods has already revolutionized fields such as catalysis and photovoltaics, where systematic search of composition space [38,39] , narrowed by theory and refined by experiment, has accelerated material discovery.…”

“…While in its original formulation, DFT is restricted to ground-state properties, excited-state properties can be accessed with constrained, ΔSCF methods or time-dependent DFT [50] . These ΔSCF methods have been successful for example in describing excited state energetics [3,23] and luminescence lineshapes [51] of defects in diamond with excellent experimental agreement. However ΔSCF methods are only useful in describing low-lying excited states and cannot capture effects such as exciton formation.…”