For the possible use of ASi-Sii defects as qubits in quantum technology, their precise local generation is an essential prerequisite. At the CiS Research Institute, local light centers in indium-doped silicon have now been generated and detected for the first time by local laser quenching.
A laser tool from Rofin-Sinar was used for the generation. The laser parameters were varied so that the temperature in the laser points was just below the pain threshold of silicon. A simple measuring station was used to detect the photoluminescence, as shown in the figures, using a cryostat. A green laser diode was used for excitation. A camera with an InGaAs image sensor, which is sensitive in the wavelength range of around 900-1700 nm, was used to detect the luminescence. A 900 nm long-pass filter was placed in front of the camera. In contrast to samples without indium doping, light centers could be generated in indium-doped CZ silicon as well as in high-resistance n-type FZ silicon implanted with indium by laser quenching.
Two exemplary photoluminescence images are shown in the figure. It is also interesting to note that some light centers are still present at room temperature. However, it is clear that the controlled generation and verification of such InSi-Sii qubits and their use still have a long way to go, with many hurdles to be overcome through a diversity of ideas.
Anyone who would like to work with us on this exciting research path is cordially invited to join us. We are open to cooperation and are always happy to hear from others.
