Microwave-assisted transport in a single-donor silicon quantum dot

Single donors in semiconductor nanostructures represent a key element to develop spin-related quantum functionalities in atomic-scale devices. Quantum transport through a single arsenic donor in the channel of a silicon nano field-effect transistor under microwave irradiation is investigated. The device is characterized at mK temperatures in the regime of Coulomb blockade. Photon-assisted tunneling and microwave-induced electron pumping regimes are revealed, respectively, at low and high microwave power. At sufficiently high power, the microwave irradiation induces tunneling through the first excited energy level of the D(0) energy of the donor. Such microwave-assisted transport at zero bias enhances the resolution of the spectroscopy of the energy levels of the donor.