Integration of more than 1 million qubits is needed to realize a general-purpose quantum computer capable of executing practical computing tasks. Of the various methods proposed, the method using electrons in solids is thought to be advantageous for integration due to its high affinity with conventional semiconductor technology, and research is underway to realize qubit integration. The efficient arrangement of enormous control wiring for manipulating large numbers of qubits is thought to be an issue for realization of qubit integrated circuits. As one solution, a method has been proposed which defines multiple qubits that can be combined into a control wiring arrangement as a single aggregate, and exchanges quantum information between multiple qubit aggregates. This requires establishment of a means to reliably transfer the quantum information of electrons between separated qubits.

One promising candidate as a means of transferring quantum information is technology to transfer single electrons using surface acoustic waves. This technology has demonstrated the ability to carry the quantum information of the spin state of electrons. However, the surface acoustic wave bursts used in previous research contain many waves that are not involved in electron transfer, and there were issues such as application of extra disturbance to electrons. Development of transfer technology that does not apply extra disturbance is demanded in order to promote qubit integration and realize reliable control of many qubits.

Researchers in AIST developed a technology for generating isolated surface acoustic wave pulses jointly with the Tokyo Institute of Technology, Institut Néel of the French National Centre for Scientific Research, and Ruhr University Bochum, and that technology was used to realize highly efficient transfer of single electrons.

Establishment of a means to transfer information between separated qubits is essential for realization of a general-purpose quantum computer. Research has been promoted on technology to transfer single electrons using surface acoustic waves as a means of transferring the quantum information of electrons. On the other hand, in previous research that transferred electrons using surface acoustic wave bursts of a certain time width, there were issues due to extra waves not involved in electron transfer. The technology developed by this research to transfer single electrons using isolated surface acoustic wave pulses enables to eliminate the adverse effects of extra surface acoustic waves on surrounding electrons. As such, it will contribute to realization of qubit integration as a highly efficient means of transferring quantum information with suppress disturbance to surrounding qubits.