Graduate Lunch Talk: Nicholas Frattini, Applied Physics Graduate Student, “Measurement at the Quantum Limit: The Josephson Parametric Converter”

The manipulation, generation and storage of quantum information has been the focus of much research lately, with the ultimate goal of building a quantum computer. One proposed implementation of such a quantum computer is through the use of superconducting microwave circuits based on the Josephson junction. These quantum circuits have the advantage of minimizing losses that could degrade the quantum information needed for quantum computation while still being engineer-able and accessible to modern day electronics. After a brief introduction to quantum computing, I will present how we design devices to both store quantum information and measure it efficiently in the circuit quantum electrodynamics architecture. Specifically, I will analyze the ultra low noise amplifier, the Josephson Parametric Converter (JPC), and show how the JPC amplifies while adding only the minimal noise required by quantum mechanics.