Quantum Mechanics From Circuits: Making The Quantum Zeno Effect

Jonathan Monroe, Department of Physics, Washington University
March 3, 2017 at 4:00 pm
204 Crow
Event Description 

Quantum mechanics offers a strange and complex world to study and explore. It supposedly provides overwhelming computational power as well as insights into the fundamental nature of reality. The process by which we experimentally investigate these systems involves a gambit of fields including nano-scale fabrication, microwave engineering, and quantum electro-dynamics. This talk will discuss the connection between these ideas and attempt to provide an intuition for how to study quantum mechanics with real-world devices. The Zeno and anti-Zeno effects are features of measurement-driven quantum evolution where frequent measurements inhibit or accelerate the decay of a quantum state. Either type of evolution can emerge depending on measurement method and the system-environment interaction. Zeno and anti-Zeno effects are basic examples of quantum control that can arise from dissipative reservoir engineering. In this experiment, we use a superconducting qubit to map out both types of Zeno effects in the presence of structured thermal noise baths and variable measurement rates. We observe both the suppression and acceleration of qubit decay as repeated dephasing measurements modulate the qubit spectrum causing it to sample different portions of the bath.