Weak-values techniques: when parameter estimation becomes easy

Precision measurements are bounded by the Standard Quantum Limit (SQL), and preparing non-classical states is often used to circumvent such a limit. In all cases, it is common to improve the precision in a parameter estimation procedure by averaging measurements on a large ensemble of identically prepared systems. However, such a task cannot be performed indefinitely due to sources of technical noise setting an experimental bound. Weak-Value Amplification (WVA) allows one to overcome some of these issues by amplifying a signal of interest above the technical-noise floor. This built-in robustness to external sources of noise relies on a weak coupling to an ancillary probe and post-selection. In this talk, we develop this idea and present a novel protocol where a WVA-like response is induced in an optical homodyne detection technique.