The fundamental building block of Quantum Information Processing (QIP) platforms is the quantum bit or qubit, which can be thought of as a quantum system with two energy levels. Transitions between these levels are accompanied by the emission/absorption of a photon, a particle of light, with the energy/frequency corresponding to the transition. For many systems, the fluctuating environment of the qubit induces spectral diffusion, a random drift in time of the emitted/absorbed photon frequency. This phenomenon limits the efficiency of photon-mediated operations between different quantum bits, and these operations are essential for the realization of large scale quantum platforms. The goal of this project is to develop protocols that will be based on externally applied control fields for the purpose of making these photon-mediated operations resilient to fluctuations in the qubit environment and thus improve the efficiency of these operations for the construction of large scale QIP platforms.
The different systems that have been successfully implemented as quantum bits each exhibit specific advantageous physical properties. Thus, for future advances towards large scale QIP platforms, using different types of qubit in a complementary manner, so that each system can be exploited for its best suited application, is a viable avenue. In this context, stationary-to-flying qubit conversion and other photon-mediated operations are essential and successful implementations depend on their efficiency. The goal of this project is to study the dynamics of quantum emitters in diffusion-inducing baths so that their optical properties can be tailored to specific QIP requirements despite deleterious effects of their environment. The PI will use a combination of analytical and computational approaches to evaluate properties of different quantum emitters and their performance in various QIP operations when they are driven by appropriate pulse and continuous wave protocols. The PI will consider different configurations of quantum emitters susceptible to spectral diffusion including two-level, three level and many-level systems and ensembles of such quantum emitters coupled to radiation baths in relevant QIP operations.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
