Science Alert June 22, 2022
Researchers in Australia have created a functional quantum processor and tested it by modeling a small molecule in which each atom has multiple quantum states. They used a scanning tunneling microscope in an ultra-high vacuum to place quantum dots with sub-nanometer precision. The trickiest parts were figuring out: exactly how many atoms of phosphorus should be in each quantum dot; exactly how far apart each dot should be; and then engineering a machine that could place the tiny dots in exactly the right arrangement inside the silicon chip. The final quantum chip contained 10 quantum dots, each made up of a small number of phosphorus atoms. Double carbon bonds were simulated by putting less distance between the quantum dots than single carbon bonds. By engineering qubit placement on the atomic scale, they provided a route to the realization and efficient characterization of multi-qubit quantum circuits based on donor qubits in silicon…read more. TECHNICAL ARTICLEÂ
High-fidelity, independent single-shot spin readout of two donor qubits. Credit: Nature volume 571, pages371–375 (2019)