Fluorescence spectrum and charge state control of divacancy qubits via illumination at elevated temperatures in 4H silicon carbide
2022 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 105, no 16, article id 165108Article in journal (Refereed) Published
Abstract [en]
Divacancy in its neutral charge state (
) in 4H silicon carbide (SiC) is a leading quantum bit (qubit) contender. Owing to the lattice structure of 4H SiC, four different VCVSi configurations can be formed. The ground and the optically accessible excited states of
configurations exhibit a high-spin state, and the corresponding optical transition energies are around ≈1.1eV falling in the near-infrared wavelength region. Recently, photoluminescence (PL) quenching has been experimentally observed for all
configurations in 4H SiC at cryogenic temperatures. It has been shown that
is converted to
and it remains in this shelving dark state at cryogenic temperatures until photoexcitation with the threshold energies or above is applied to convert
back to
. In this study, we demonstrate both in experiments and theory that the threshold energy for reionization is temperature dependent. We carry out density functional theory (DFT) calculations in order to investigate the temperature dependent reionization spectrum, i.e., the spectrum of the
process. We find that simultaneous optical reionization and qubit manipulation can be carried out at room temperature with photoexcitation at the typical excitation wavelength used for readout of the divacancy qubits in 4H SiC, in agreement with our experimental data. We also provide the analysis of the PL spectrum of
, characteristic for each
configuration in 4H SiC, using the Huang-Rhys theory, and find that one configuration in 4H SiC stands out in terms of the strength of coherent emission among the four configurations.
Place, publisher, year, edition, pages
AMER PHYSICAL SOC , 2022. Vol. 105, no 16, article id 165108
National Category
Condensed Matter Physics
Identifiers
URN: urn:nbn:se:liu:diva-185850DOI: 10.1103/PhysRevB.105.165108ISI: 000804851000003OAI: oai:DiVA.org:liu-185850DiVA, id: diva2:1670970
Note
Funding Agencies|New National Excellence Program of the Ministry for Innovation and Technology from the National Research, Development and Innovation Fund [UNKP-20-4]; National Research, Development, and Innovation Office for Hungary of the National Excellence Program of Quantum-coherent materials project [KKP129866]; National Research, Development, and Innovation Office for Hungary of the EU QuantERA Nanospin project [127902]; National Research, Development, and Innovation Office for Hungary of the National Quantum Technology Program [2017-1.2.1-NKP-2017-00001]; Ministry of Innovation and Technology of Hungary; EU Commission for the H2020 Quantum technology Flagship projects ASTERIQS [820394]; EU H2020 project QuanTELCO [862721]; Swedish Research Council [VR 2016-05362, VR 2016-04068, 2018-05973]; Knut and AliceWallenberg Foundation [KAW2018.0071]; Hungarian Governmental Information Technology Development Agency; PRACE aisbl
2022-06-162022-06-162022-06-17