THE QUANTUM FENCE INTRUSION DETECTION WITH QUANTUM MECHANICS At ORNL, we are using quantum mechanics to detect intruders across a physical perimeter. While a sensor based on classical physics is vulnerable to counterfeiting attacks, a quantum sensor uses entanglement to detect an intruder’s counterfeiting attempts. The quantum fence can secure safes, seals, and locks, and enable tamper-evident perimeter protection systems. Classical Sensor Quantum Sensor Sensors using classical fields are The quantum fence uses entangled vulnerable to counterfeiting attacks: when photons to foil counterfeiting: because it’s an intruder perfectly replicates the impossible for an intruder to replicate transmitted field, the sensor cannot entanglement, counterfeiting attempts are detect the difference. signaled by a detected absence of entanglement. Classical Quantum Transmitter Transmitter Classical Field Entangled Field Attack Attack Field Replicator Replicator Classical Quantum Receiver Receiver Alarm Quantum Communication Laboratory The Quantum Communication Laboratory applies quantum optics to communication protocols like quantum teleportation and entanglement swapping. These fundamental studies support applications, e.g., quantum key distribution and the quantum fence. POLARIZATION-ENTANGLED PHOTONS 1 "12 = d# d# $ h1(#),v2 (# $) 2 % % ( + v1("),h2(" #) ) ! ! A nonlinear optical waveguide stimulates Technical Points of Contact Travis Humble (presenting) spontaneous parametric down conversion Center for Engineering Science Advanced Research of a pulsed laser. SPDC provides the Computer Science and Mathematics Division [email protected] multimode polarization-entangled photons www.ornl.gov/~hqt that are used to implement the quantum Warren Grice and Ryan Bennink fence. Center for Quantum Information Science Computational Sciences and Engineering Division [email protected] and [email protected].