Advanced Development for Defense Science and Technology: Measurement Tools for Quantum Information Processing

Quantitative and visually intuitive information is critical to understanding, designing, and verifying the operation of any complex system. Measurement tools, such as vector signal analyzers which allow the visualization of radio frequency signal constellations, are now an indispensable part of modern engineering methods. There is intense interest in exploiting the special properties of quantum states for applications such as quantum communication and computing. However, the very properties of quantum states that make them useful also make them difficult to measure. Quantum state tomography is a measurement tool which allows for complete characterization of quantum states. Although great progress has been made in researching quantum tomography techniques, no commercial equipment exists and current demonstrations of the method tend to be slow, thereby providing little information about the quantum state drift over time. Advances in the field of quantum information are severely hampered because every development group must build their own tools including even basic measurement devices. It is the goal of this Phase-II SBIR to develop a real-time photonic quantum state tomography system. The prototype will measure both polarization-mode and time-mode signals at high speeds (~1s) and display the complex state information to the user in an intuitive way.