Polaron Effects on the Optical Properties of Semiconductor Based Spin-Photon Interfaces

Understanding the effects of vibrational modes on solid-state qubits proves a major challenge in developing robust spin-photon interfaces for semiconductor quantum computing architectures. Donor spins in silicon are known to exhibit remarkably long-coherence times, making them attractive candidates for qubits, however the semiconductor environment introduces strong electron-phonon interactions which adversely affect the fidelity of the spin-photon interface, and therefore our ability to entangle qubits and perform quantum gate computations. In order to better understand the role of electron-phonon couplings in these systems, we study a microscopic model that captures the physical mechanisms inherent to these interactions in semiconductor substrates. We report on calculated fluorescence emission spectra that closely reproduce experimentally observed phonon sideband formation, as well as zero-temperature optical transition linewidth broadening due to non-local electron-phonon couplings. We explore a range of parameters permitted by the model and discuss implications for experimental design.