Defects as qubits in3C−and4H−SiC

Abstract

We employ hybrid density functional calculations to search for defects in different polytypes of SiC that may serve as qubits for quantum computing. We explore the divacancy in 4H-and 3C-SiC, consisting of a carbon vacancy adjacent to a silicon vacancy, and the NV center in 3C-SiC, in which the substitutional NC sits next to a Si vacancy (NC-VSi). The calculated excitation and emission energies of the divacancy in 4H-SiC are in excellent agreement with experimental data, and aid in identifying the 4 unique configurations of the divacancy with the 4 distinct zero-phonon lines observed experimentally. For 3C-SiC, we identify the paramagnetic defect that was recently shown to maintain a coherent quantum state up to room temperature as the spin-1 neutral divacancy. Finally, we show that the (NC-VSi) − center in 3C-SiC is highly promising for quantum information science, and we provide guidance for identifying this defect.

First principles predictions of magneto-optical data for semiconductor point defect identification: the case of divacancy defects in 4H–SiC

“…The ZFS parameter was calculated using the data from a 1200 atom supercell, with Γ-point sampling, using the PBE functional. Our computational results also agree with a calculation by Gordon et al [34] using the HSE06 functional on a 96 atom supercell with 2×2×2 k-point grid. As the authors remarked it is not possible to use only ZPL to identify the different configurations due to the low accuracy of the calculations.…”

“…The identification of such non-equivalent configurations is particularly challenging. For the non-equivalent configurations of divacancy related qubits in 4H-SiC two contradictory identifications have been presented, which rely on either the calculated zero-phonon photoluminescence (ZPL) lines [34] or the zero-field splitting parameter (ZFS) [35]. Furthermore, recently more divacancy related centers were reported than the possible number of non-equivalent divacancy configurations in SiC [20,21], which makes the identification even more puzzling.…”

Designing defect-based qubit candidates in wide-gap binary semiconductors for solid-state quantum technologies

“…As a validation step of the computational strategy applied to LMI-vacancy complexes, we first applied the DDH hybrid functionals to the diamond NV center and a divacancy defect (the (hh)-divacancy) in 4H-SiC, which have the same C 3v symmetry as that of the complexes studied here; we compared our results with those already present in the literature 28,62,63 and found good agreement (see Fig. S2).…”

Large‐Scale Plasmonic Hybrid Framework with Built‐In Nanohole Array as Multifunctional Optical Sensing Platforms

“…[15][16][17][18][19] III) E-beam or ion-beam lithography patterning. [20][21][22] IV) Our two-step templated method for fabricating large-scale nanohole array. the fully etched TiN nanohole films grown on (001) MgO.…”

“…[17][18][19] On the other hand, top-down approaches including focused ion-beam milling and e-beam lithography (Figure 1 III) have been used to process most of the nanohole structures reported. [20][21][22] The feature size down to ≈20 nm with perfect periodicity over hundreds of micrometers has been demonstrated, along with various geometries including elliptical or squared-hole, [22] double-hole, patched nanohole arrays [6,23] nanoscale-voids, [24] as well as nanotrenches. [25,26] However, these top-down lithography methods involve tedious writing and processing, and limited scalability.…”