Gentle Measurement of Quantum States and Differential Privacy

I’ll discuss a recent connection between two seemingly unrelated problems: how to measure a collection of quantum states without damaging them too much (“gentle measurement”), and how to provide statistical data without leaking too much about individuals (“differential privacy,” an area of classical CS). This connection leads, among other things, to a new protocol for “shadow tomography” of quantum states (that is, answering a large number of questions about a quantum state given few copies of it).