Optical Control of Spin-Valley-Orbital States of Group-V Donors in Silicon
Michael Gullans, Jacob M. Taylor
We show how to to achieve spin-selective excitation of the valley-orbit states of group-V donors (P, As, Sb, Bi) in silicon using optical fields. We consider two approaches based on exploiting resonant, far-infrared (IR) transitions of the neutral donor or resonant, near-IR excitonic transitions. For far-IR light, we calculate the dipole matrix elements between the valley-orbit and spin-orbit split states for all the donors. We then calculate the maximum rate and amount of electron-nuclear spin-polarization achievable through optical pumping with circularly polarized light. We find this approach is most promising for Bi donors due to their large spin-orbit and valley-orbit interactions. Using near-IR light, spin-selective excitation is possible for all the donors by driving a two-photon Λ- transition from the ground state to higher orbitals with even parity. Using externally applied electric fields or strain, we show it is also possible to achieve similar, spin-selective Λ-transition to odd-parity excited states. We anticipate these results will be useful for future spectroscopic investigations of donors, quantum control and state preparation of donor spin qubits, and for developing a coherent interface between donor spin qubits and single photons.
and Taylor, J.
Optical Control of Spin-Valley-Orbital States of Group-V Donors in Silicon, Physical Review B, [online], https://doi.org/10.1103/PhysRevB.92.195411
(Accessed September 30, 2023)