The Strength of the Weak: The Uncertainty Principle and More-Direct Access to the Wave Function through Weak Measurements

TL;DR

This paper reviews recent advances in weak measurement techniques that allow more direct access to the quantum wavefunction, minimally disturbing the system and providing new insights into the uncertainty principle.

Contribution

It discusses recent empirical work on weak measurements and explores their implications for understanding the wavefunction and the uncertainty principle.

Findings

Weak measurements minimally disturb the wavefunction.

Post-selection enables indirect access to the wavefunction.

Weak measurement techniques offer new experimental possibilities.

Abstract

Recent empirical work in the field of 'weak measurements' has yielded novel ways of more directly accessing and exploring the quantum wavefunction. Measuring either position or momentum for a photon in a 'weak' manner yields a wide range of possible values for the measurement, and can be done in such a way as to only minimally effect the wavefunction rather than to collapse it to a specific precise value. Measuring the other complementary variable (position or momentum) precisely at a later time ('post-selection') and averaging the weak measurements can yield information about the wavefunction that is not directly experimentally obtainable using other methods. This paper discusses two recent papers on weak measurement in the context of the uncertainty principle more broadly, and considers some possibilities for further research.