Abstract for Talk 1:

Optimizing quantum transport over noisy networks is important to the development of advanced energy and information processing technologies such as in quantum communication or solar cells. In this project, we focus on transport of a single excitation in a one-dimensional chain with long range couplings, and we aim to optimize the chain's energy profile towards high transport flux. The system’s interaction with its environment is modeled through the Lindblad master equation with fixed dephasing rates. We study the optimal chain design under infinite temperature conditions, utilizing Optax’s optimistic gradient descent and JAX’s automatic differentiation. As a case study, we test the optimization approach against complete simulations for a three-site chain. We show that in the local-site local-decoherence model (representing an infinite temperature bath), transport is insensitive to the position of the central level when couplings beyond nearest neighbors are included. I will also present results of ongoing work, focusing on optimization of longer networks. I will conclude by discussing extensions to muti excitations and higher dimension networks. 

Abstract for Talk 2

Quantum Entanglement and Squeezing have been successfully demonstrated using bulk optics.  However, for practical realization both of these must be capable of being realized on-chip for applications such as sensing, computing, imaging, and communications.  Entangled photon sources and squeezing sources are the two primary components that will be focused on in this talk.  Two critical material characteristics to build these structures are low propagation loss and high nonlinearity.  Furthermore, the materials used need to be readily available to be grown and etched into nanostructures with low critical dimensions in commercial foundries allows for easy fabrication and integration of these nanophotonic components on a single chip.  Experimental results for polarization entangled photons with a high fidelity and concurrence based on effective index guided aluminum gallium arsenide (AlGaAs) on chip laser width high tunability will be shown.  Finally, designs for on chip squeezing will be discussed using resonant silicon nanostructures that enhance the electric field amplitude, leading to higher nonlinear conversion efficiency and hence higher squeezing levels.