QRC seminars - Stephen P. Walborn

Title:

Multicore optical fibers for quantum information processing

Abstract:

Photonic systems are the natural choice for distributing quantum information, since light can be easily routed from one location to another.  This has allowed for the demonstration of quantum information protocols over a few hundreds of meters in optical fibers or free space. Future quantum information networks will most likely need to be compatible with the telecommunications infrastructure. In this regard, the looming capacity crunch in optical fiber communication has fueled much interest in space division multiplexing technology.  One promising candidate are multi-core optical fibers, which have multiple fiber cores within the same cladding. These fibers are particular interesting in the quantum regime, allowing for higher-dimensional encoding with increased phase stability. Here I present an brief overview of current research in the field and discuss our efforts at University of Concepción to employ multi-core fibers for quantum information processing.  In particular, I will present several useful devices, including multi-core fiber beam splitters. I will discuss their use for high-quality multi-path interference of single and multiple photons, experiments in indefinite causal order, and performing generalized measurements. 

Bio:

Steve got his Master’s and PhD at the Federal University of Minas Gerais, Belo Horizonte, Brasil, under the supervision of Prof. Carlos Monken. He then realized post-docs at the Federal University of Rio de Janeiro, where he was then a professor from 2007 to 2019. In 2019 he moved to the University of Concepción, Chile. His work focuses on entangled photons and their use in studying quantum mechanics and quantum information.