Applied Physics Seminar

Abstract: The cooperative behavior of interacting systems gives rise to interesting physical phenomena like emergent synchronization, Dicke superradiance, and long-range coherent energy transport. In practical applications, these features may be used to enhance the performance of precision measurements, quantum memories, and sensor-based applications. In this talk, I will discuss our recent work showing how correlated dissipation and subradiance gives rise to ideal performance metrics in power extraction devices. According to the maximum power transfer theorem, designing a system with both optimal power transfer and efficiency is unachievable. This results in a fundamental trade-off that has long been an obstacle for classical energy transfer devices. Here, I will show that atomic subradiance provides a means of overcoming this trade-off. I will discuss our result using a simple theoretical model involving a coherently-driven two-atom system, outlining the key design principles required to achieve the optimization of both efficiency and maximum output power. This result may have important implications in photovoltaic, thermo-photovoltaic, as well as wireless power transfer technologies. In the second part of the talk, I will present a first-principles nanophotonic approach for controlling quantum correlations and interatomic interactions. Our work reveals a new class of excited-state, broadband, angle-dependent and singular interactions referred to as Super-Coulombic interactions that emerge in hyperbolic media. This theoretical prediction motivated an intense search for the effect and was recently confirmed by several experimental demonstrations.
1. Cortes, C.L., Jacob, Z. Overcoming the power-efficiency trade-off using atomic subradiance. In preparation (2018).
2. Cortes, C.L., Jacob, Z. Fundamental efficiency bound for coherent energy transfer in nanophotonics. arXiv:1709.04478 (2017).
3. Cortes, C.L., Jacob, Z. Super-Coulombic atom-atom interactions in hyperbolic media. Nature Communications, 8, 14144, (2017).

Biography: Cristian completed his Ph.D. in Electrical and Computer Engineering from Purdue University in 2018 and received his B.Sc. in Engineering Physics from the University of Alberta in Canada (2012). His research interests comprise the topics of open quantum systems, quantum noise phenomena, metamaterials, nanophotonics, and quantum optics research. His most recent work has focused on understanding how quantum correlations can be used to improve the performance metrics (e.g. speed, efficiency, power output) of optical and electronic devices. He is a recipient of the Alexander Graham Bell graduate scholarship, Purdue's Outstanding Research Award, and the SPIE Optics and Photonics scholarship awarded for potential long-term contributions.