Our research team has recently achieved a significant breakthrough in the field of silicon-based quantum technology by realising fast photoionisation detection of individual erbium ions in a silicon nano-transistor. Each ionisation event can be detected with a time resolution of less than 100 nanoseconds. This research achievement, titled "Photoionisation detection of a single Er3+ ion with sub-100-ns time resolution", has been published in the journal "National Science Review".
Efficient detection of individual optical centres is crucial for applications in quantum computing, sensing, and single-photon generation. For example, nitrogen-vacancy (NV) centres in diamond have made breakthroughs in high-precision magnetic field measurement. The detection of NV centres relies on observing their spin-correlated fluorescence. Similarly, optical centres in silicon carbide and rare earth ions in solids also have similar detection mechanisms. However, the readout of these systems requires collecting a sufficient number of photons as detection signals, which limits the fidelity of spin state readout. In contrast, the electrical readout methods commonly used in quantum electronic devices provide higher readout fidelity within shorter time intervals.
Prof Chunming Yin and his team previously achieved photoionisation detection of individual erbium ions in silicon-based single-electron transistors in 2013. However, the readout speed of photoionisation events was significantly limited by the bandwidth of DC current measurements. In this latest work, we employed radiofrequency reflectometry and successfully realised fast photoionisation detection of individual erbium ions in silicon-based single-electron transistors (Fig. 1), with each detection event having a time resolution better than 100 nanoseconds. Based on this technique, we also studied the optical excited state lifetime of individual erbium ions in silicon-based nanodevices.
Figure 1: a) Fast photoionisation detection of individual erbium ions in in a silicon nano-transistor. b) Three photoionisation events detected for an individual erbium ion (Fig. 1b).
This radiofrequency reflectometry detection technique, combined with individual optical centres, provides new possibilities for scalable optical quantum systems. Moreover, this method holds promise for achieving rapid readout of other individual optical centres in solids, thereby advancing the applications of individual optical centres in scalable quantum systems and high-precision sensing.
Mr Yangbo Zhang, a PhD student from our team, served as the first author, and Prof Chunming Yin was the corresponding author. This work was supported by the Ministry of Science and Technology (China) and Anhui Province.
Link to the article:https://doi.org/10.1093/nsr/nwad134
