Quantum technology is quantifiable in qubits, which are the most basic unit of data in quantum computers. The operation of qubits is affected by the quantum coherence time required to maintain a quantum wave state.

Scientists have hypothesized that moir茅 excitons鈥�electron-hole pairs confined in moir茅 interference fringes which overlap with slightly offset patterns鈥攎ay function as qubits in next-generation nano-semiconductors.

However, due to diffraction limits, it has not been possible to focus light enough in measurements, causing optical interference from many moir茅 excitons.

To solve this, Kyoto University researchers have developed a new method of reducing these moir茅 excitons to measure the quantum coherence time and realize quantum functionality. The team has observed changing photoluminescence signals of moir茅 excitons following the fabrication process. The work is in the journal Nature Communications.

"We combined electron beam microfabrication techniques with reactive ion etching. By utilizing Michelson interferometry on the emission signal from a single moir茅 exciton, we could directly measure its quantum coherence time," Kazunari Matsuda of KyotoU's Institute Advanced Energy explains.

The results show that the quantum coherence of a single moir茅 exciton remains steady at -269掳C for more than 12 picoseconds, 10-times longer than that of an exciton in the parent material, a two-dimensional semiconductor. The confined moir茅 excitons in interference fringes prevent loss of quantum coherence.

"We plan to establish a foothold for the next phase of experiments for advancing quantum computing and other quantum technologies in the next generation of nano-semiconductors," adds Matsuda.