Title: Making Better Qubits out of Spectrally Noisy Solid State Quantum Emitters

Abstract: Many of the systems that are promising implementations of qubits for quantum information processing are solid state quantum emitters. Most of these systems are subject to spectral diffusion: the random drift of the emission/absorption spectrum away from a set target frequency. This uncontrolled dynamics is due to the fluctuations (strain, charge or spin) in the surrounding bath and adversely affects many fundamental operations for scalable quantum information processing platforms. Essential photon-mediated operations can be particularly sensitive to these uncontrolled variations.  In particular, the ability to entangle distant quantum nodes is essential for the construction of quantum networks and the realization of basic quantum gates. For solid-state quantum emitters, entanglement generation is often achieved by photon interference and can be highly inefficient for these qubits because of spectral diffusion. We will discuss optical properties of quantum emitters in dynamic environments when they are driven by suitable external fields and show that the emission/absorption spectrum can be kept fixed despite the influence of the environment. Furthermore, we will show that photon indistinguishability assessed through two-photon interference can be greatly enhanced by suitable pulse control protocols.

Host: Lex Kemper