Kwiat, Paul G.

Person Preferred Name
Kwiat, Paul G.
Model
Digital Document
Publisher
Florida Atlantic University
Description
In this effort, we present progress toward demonstrating a Decoy-State Quantum Key Distribution (QKD) source based on a polarization-modulator and a wavelength-stable attenuated pulsed laser. A three-state QKD protocol is achieved by preparing particular quantum polarization states. The polarization-modulator-based QKD source improves security by removing several sources of side-channel attacks that exist when multiple sources are used to generate different QKD states. Here we present a QKD source design and an evaluation of critical subsystems characterized by the Quantum Bit Error Rate, Quantum State tomography, and achievable Key Rates. The QKD source is intended to operate within compact Size, Weight, and Power constraints. The Polarization-Modulator QKD source has applications in future mobile quantum networks such as Unmanned-Aerial Vehicles (UAV) and autonomous vehicles, as well as fixed fiber-based quantum networks.
Quantum mechanics can produce correlations that are stronger than classically allowed. This stronger-than-the-classical correlation is the “fuel” for quantum computing. In 1991 Schumacher forwarded a beautiful geometric approach, analogous to the well-known result of Bell, to capture the non-classicality of this correlation for a singlet state. He used well-established information distance defined on an ensemble of identically–prepared states. He calculated that for certain detector settings used to measure the entangled state, the resulting geometry violated a triangle inequality —a violation that is not possible classically. This provided novel information–based on geometric Bell inequality in terms of a “covariance distance.” Here we experimentally reproduce his construction and demonstrate a definitive violation for a Bell state of two photons based on the usual spontaneous parametric down-conversion in a paired BBO crystal. The state we produced had visibility of Vad = 0.970}0.012. We discuss generalizations to higher dimensional multipartite quantum states.