No Arabic abstract
We report on acoustically driven spin resonances in atomic-scale centers in silicon carbide at room temperature. Specifically, we use a surface acoustic wave cavity to selectively address spin transitions with magnetic quantum number differences of $pm$1 and $pm$2 in the absence of external microwave electromagnetic fields. These spin-acoustic resonances reveal a non-trivial dependence on the static magnetic field orientation, which is attributed to the intrinsic symmetry of the acoustic fields combined with the peculiar properties of a half-integer spin system. We develop a microscopic model of the spin-acoustic interaction, which describes our experimental data without fitting parameters. Furthermore, we predict that traveling surface waves lead to a chiral spin-acoustic resonance, which changes upon magnetic field inversion. These results establish silicon carbide as a highly-promising hybrid platform for on-chip spin-optomechanical quantum control enabling engineered interactions at room temperature.
Solid-state color centers with manipulatable spin qubits and telecom-ranged fluorescence are ideal platforms for quantum communications and distributed quantum computations. In this work, we coherently control the nitrogen-vacancy (NV) center spins in silicon carbide at room temperature, in which telecom-wavelength emission is detected. We increase the NV concentration six-fold through optimization of implantation conditions. Hence, coherent control of NV center spins is achieved at room temperature and the coherence time T2 can be reached to around 17.1 {mu}s. Furthermore, investigation of fluorescence properties of single NV centers shows that they are room temperature photostable single photon sources at telecom range. Taking advantages of technologically mature materials, the experiment demonstrates that the NV centers in silicon carbide are promising platforms for large-scale integrated quantum photonics and long-distance quantum networks.
Spins in solids are cornerstone elements of quantum spintronics. Leading contenders such as defects in diamond, or individual phosphorous dopants in silicon have shown spectacular progress but either miss established nanotechnology or an efficient spin-photon interface. Silicon carbide (SiC) combines the strength of both systems: It has a large bandgap with deep defects and benefits from mature fabrication techniques. Here we report the characterization of photoluminescence and optical spin polarization from single silicon vacancies in SiC, and demonstrate that single spins can be addressed at room temperature. We show coherent control of a single defect spin and find long spin coherence time under ambient conditions. Our study provides evidence that SiC is a promising system for atomic-scale spintronics and quantum technology.
The silicon vacancy in silicon carbide is a strong emergent candidate for applications in quantum information processing and sensing. We perform room temperature optically-detected magnetic resonance and spin echo measurements on an ensemble of vacancies and find the properties depend strongly on magnetic field. The spin echo decay time varies from less than 10 $mu$s at low fields to 80 $mu$s at 68 mT, and a strong field-dependent spin echo modulation is also observed. The modulation is attributed to the interaction with nuclear spins and is well-described by a theoretical model.
In this paper, we study the electron spin decoherence of single defects in silicon carbide (SiC) nuclear spin bath. We find that, although the natural abundance of $^{29}rm{Si}$ ($p_{rm{Si}}=4.7%$) is about 4 times larger than that of $^{13}{rm C}$ ($p_{rm{C}}=1.1%$), the electron spin coherence time of defect centers in SiC nuclear spin bath in strong magnetic field ($B>300~rm{Gauss}$) is longer than that of nitrogen-vacancy (NV) centers in $^{13}{rm C}$ nuclear spin bath in diamond. The reason for this counter-intuitive result is the suppression of heteronuclear-spin flip-flop process in finite magnetic field. Our results show that electron spin of defect centers in SiC are excellent candidates for solid state spin qubit in quantum information processing.
We demonstrate that the spin of optically addressable point defects can be coherently driven with AC electric fields. Based on magnetic-dipole forbidden spin transitions, this scheme enables spatially confined spin control, the imaging of high-frequency electric fields, and the characterization of defect spin multiplicity. While we control defects in SiC, these methods apply to spin systems in many semiconductors, including the nitrogen-vacancy center in diamond. Electrically driven spin resonance offers a viable route towards scalable quantum control of electron spins in a dense array.