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

@article{Davidsson2018FirstPP,
  title={First principles predictions of magneto-optical data for semiconductor point defect identification: the case of divacancy defects in 4H–SiC},
  author={Joel Davidsson and Viktor Iv'ady and Rickard Armiento and Nguyen Tien Son and {\'A}d{\'a}m Gali and Igor A. Abrikosov},
  journal={New Journal of Physics},
  year={2018},
  volume={20}
}
Study and design of magneto-optically active single point defects in semiconductors are rapidly growing fields due to their potential in quantum bit (qubit) and single photon emitter applications. Detailed understanding of the properties of candidate defects is essential for these applications, and requires the identification of the defects microscopic configuration and electronic structure. In multi-component semiconductors point defects often exhibit several non-equivalent configurations of… 
First-principles calculations of Stark shifts of electronic transitions for defects in semiconductors: the Si vacancy in 4H-SiC
TLDR
A theoretical framework for studying electric field effects on defect-related electronic transitions, based on density functional theory calculations with periodic boundary conditions is described, finding an approximately linear field response for the zero-phonon transitions of V Si involving the decay from the first excited state.
First principles calculation of spin-related quantities for point defect qubit research
Point defect research in semiconductors has gained remarkable new momentum due to the identification of special point defects that can implement qubits and single photon emitters with unique
Stabilization of point-defect spin qubits by quantum wells
TLDR
It is shown that embedding artificial atoms in stacking faults can actually improve their optical properties, making them function even more like true atoms, paving the way for the development of robust single-photon sources and spin qubits.
Identification of divacancy and silicon vacancy qubits in 6H-SiC
Point defects in semiconductors are relevant for use in quantum technologies as room temperature qubits and single photon emitters. Among suggested defects for these applications are the negatively
Theoretical polarization of zero phonon lines in point defects
  • J. Davidsson
  • Physics
    Journal of physics. Condensed matter : an Institute of Physics journal
  • 2020
TLDR
A method for calculating the frequency, intensity, and polarization of the zero phonon line is presented and the importance of using wave functions from both the ground and excited state is shown.
Material platforms for defect qubits and single-photon emitters
Quantum technology has grown out of quantum information theory and now provides a valuable tool that researchers from numerous fields can add to their toolbox of research methods. To date, various
Spin–spin interactions in defects in solids from mixed all-electron and pseudopotential first-principles calculations
Understanding the quantum dynamics of spin defects and their coherence properties requires an accurate modeling of spin-spin interaction in solids and molecules, for example by using spin
Anomalous zero-field splitting for hole spin qubits in Si and Ge quantum dots
An anomalous energy splitting of spin triplet states at zero magnetic field has recently been measured in germanium quantum dots. This zero-field splitting could crucially alter the coupling between
Ab initio theory of the nitrogen-vacancy center in diamond
Abstract The nitrogen-vacancy (NV) center in diamond is a solid-state defect qubit with favorable coherence time up to room temperature, which could be harnessed in several quantum-enhanced sensor
...
...

References

SHOWING 1-10 OF 65 REFERENCES
Design of defect spins in piezoelectric aluminum nitride for solid-state hybrid quantum technologies
TLDR
A strain-driven scheme to rationally design defect spins in functional ionic crystals, which may operate as potential qubits in wide-band gap semiconductors, paving the way to controlling the spin properties of defects in ionic systems for potential spintronic technologies.
Room temperature coherent control of defect spin qubits in silicon carbide
TLDR
It is demonstrated that several defect spin states in the 4H polytype of SiC (4H-SiC) can be optically addressed and coherently controlled in the time domain at temperatures ranging from 20 to 300 kelvin.
First-principles calculations for point defects in solids
Point defects and impurities strongly affect the physical properties of materials and have a decisive impact on their performance in applications. First-principles calculations have emerged as a
Spin and photophysics of carbon-antisite vacancy defect in 4H silicon carbide: A potential quantum bit
Silicon carbide with engineered point defects is considered as very promising material for the next generation devices, with applications ranging from electronics and photonics to quantum computing.
Theory of spin-conserving excitation of the N-V(-) center in diamond.
TLDR
By using hybrid density-functional-theory calculations in a large supercell, this work can reproduce the zero-phonon line and the Stokes and anti-Stokes shifts, yielding a complete picture of the spin-conserving excitation of this defect.
Properties of nitrogen-vacancy centers in diamond: the group theoretic approach
We present a procedure that makes use of group theory to analyze and predict the main properties of the negatively charged nitrogen-vacancy (NV) center in diamond. We focus on the relatively low
High-fidelity spin measurement on the nitrogen-vacancy center
Nitrogen-vacancy (NV) centers in diamond are versatile candidates for many quantum information processing tasks, ranging from quantum imaging and sensing through to quantum communication and
Polytype control of spin qubits in silicon carbide
TLDR
It is shown that the 4H, 6H and 3C polytypes of SiC all host coherent and optically addressable defect spin states, including states in all three with room-temperature quantum coherence, which shows that crystal polymorphism can be a degree of freedom for engineering spin qubits.
Room temperature coherent spin alignment of silicon vacancies in 4H- and 6H-SiC.
TLDR
The data show that the probed silicon vacancy spin ensemble can be prepared in a coherent superposition of the spin states, and make the silicon vacancy in SiC a very favorable defect for spintronics, quantum information processing, and magnetometry.
Ultralong spin coherence time in isotopically engineered diamond.
TLDR
Here, it is demonstrated the synthesis and application of ultrapure isotopically controlled single-crystal chemical vapour deposition (CVD) diamond with a remarkably low concentration of paramagnetic impurities, and single electron spins show the longest room-temperature spin dephasing times ever observed in solid-state systems.
...
...