Coherent electrical readout of defect spins in silicon carbide by photo-ionization at ambient conditions

Abstract

Quantum technology relies on proper hardware, enabling coherent quantum state control as well as efficient quantum state readout. In this regard, wide-bandgap semiconductors are an emerging material platform with scalable wafer fabrication methods, hosting several promising spin-active point defects. Conventional readout protocols for defect spins rely on fluorescence detection and are limited by a low photon collection efficiency. Here, we demonstrate a photo-electrical detection technique for electron spins of silicon vacancy ensembles in the 4H polytype of silicon carbide (SiC). Further, we show coherent spin state control, proving that this electrical readout technique enables detection of coherent spin motion. Our readout works at ambient conditions, while other electrical readout approaches are often limited to low temperatures or high magnetic fields. Considering the excellent maturity of SiC electronics with the outstanding coherence properties of SiC defects, the approach presented here holds promises for scalability of future SiC quantum devices.

Electrical charge state identification and control for the silicon vacancy in 4H-SiC

“…More recently, point defects in silicon carbide (4H-SiC) have gained attention as a more devicefriendly alternative, offering a platform to merge existing semiconductor processing capabilities with the quantum technology of the future. 9,10 Recent testaments to the viability of 4H-SiC as a quantum host include single-photon emission from, and coherent control of, the silicon vacancy (V Si ), [11][12][13] carbon antisitevacancy pair (C Si V C ), 14 transition metal 15 and silicon-carbon divacancy (V Si V C ) 16 spins at room temperature, as well as observations of millisecond spin coherence times for V Si 17 and V Si V C 18 at cryogenic temperatures. Hitherto, the desired quantum properties of defects in 4H-SiC have been established for specific charge states only, with the remainder being dark and exhibiting no identified spin signals.…”

Influence of Irradiation on Defect Spin Coherence in Silicon Carbide

“…SiC itself is a technologically highly developed wide band gap semiconductor with unique mechanical, electrical and optical properties, that make it very attractive for various electronic and optoelectronic applications under extreme conditions. Therefore, it is a unique platform to implement hybrid quantum systems, where defect spins can be coupled to the eigenmodes of mechanical resonators [31,32] and photonic cavities [33][34][35][36] or integrated into photoelectronic circuits [37][38][39]. Because SiC is a bio-compatible material, the fabrication of spincarrying defects in SiC nanocrystals [40,41] gives an opportunity for in-vivo imaging of chemical processes.…”

Single-Photon Sources Based on Novel Color Centers in Silicon Carbide P–I–N Diodes: Combining Theory and Experiment

“…The electron and hole capture cross sections obtained using our approach can help to identify the color center, which can be done by comparing the capture cross sections obtained using the DFT and similar techniques with the capture cross sections retrieved from the experiment using our method. The ability to find the capture cross sections by Table 2 Electron capture constant c n + and electron capture cross section σ n + by the positively charged color center and hole capture constant c p 0 and hole capture cross section σ p 0 by the neutral color center obtained from the experimental data using the model of the SPEL process that involves the (0) and (+ 1) charges states S (cm s −1 ) c n + (cm 3 s −1 ) σ n + (cm 2 ) c p 0 (cm 3 s −1 ) σ p 0 (cm 2 ) 0 2.7 × 10 −8 1.5 × 10 −15 1.7 × 10 −9 1.5 × 10 −16 10 4 3.5 × 10 −8 1.9 × 10 −15 2.1 × 10 −9 1.9 × 10 −16 2 × 10 4 4.1 × 10 −8 2.3 × 10 −15 2.6 × 10 −9 2.3 × 10 −16 5 × 10 4 5.8 × 10 −8 3.2 × 10 −15 4.3 × 10 −9 3.8 × 10 −16 1 × 10 5 8.4 × 10 −8 4.7 × 10 −15 8.5 × 10 −9 7.5 × 10 −16 2 × 10 5 1.2 × 10 −7 6.9 × 10 −15 1.7 × 10 −8 1.5 × 10 −15 a novel color center is also of crucial importance for the design and development of quantum optoelectronic devices based on novel color centers where charge state switching, control, or stabilization is required, such as for protecting quantum memories based on color centers [56], electrical readout of the spin state of the color center at a high repetition rate [57], pulsed electrical single-photon sources [58], or photocurrent detected magnetic resonance (PDMR) devices [59,60].…”

“…The electron and hole capture cross sections obtained using our approach can help to identify the color center, which can be done by comparing the capture cross sections obtained using the DFT and similar techniques with the capture cross sections retrieved from the experiment using our method. The ability to find the capture cross sections by a novel color center is also of crucial importance for the design and development of quantum optoelectronic devices based on novel color centers where charge state switching, control, or stabilization is required, such as for protecting quantum memories based on color centers [ 56 ], electrical readout of the spin state of the color center at a high repetition rate [ 57 ], pulsed electrical single-photon sources [ 58 ], or photocurrent detected magnetic resonance (PDMR) devices [ 59 , 60 ].…”