Physics Colloquium

Quantum mechanical systems with two levels arise in multiple disciplines of physics, astronomy, chemistry, computer science, and materials science.  The rules that govern the process and outcomes of measurements of quantum two level systems give us insight into more complex scenarios as well as the power and limitations of quantum computers.  In particular, what is known as the purity of a quantum state is an important aspect of near-term quantum-enhanced sensors and processors, though it lags behind the performance achieved for other operational primitives of these systems.  Focusing on trapped atomic ions as near-ideal quantum two-level systems, I will discuss both the improvement of measurements of quantum states as well as their utility for enhancing the functioning of other processes in these systems.