Protection mechanism

Olivia Nicoletti

Shan Gao

This article introduces the method of protective measurement and discusses its deep implications for the foundations of quantum mechanics. It is argued that protective measurement implies that the wave function of a quantum system is a representation of the physical state of the system, and a further analysis of the mass and charge distribution of the system, which is measurable by protective measurements, may also help determine what physical state the wave function represents. 1

Shan Gao

Protective measurements offer an intriguing method for measuring the wave function of a single quantum system. With contributions from leading physicists and philosophers of physics - including two of the original discoverers of this important method - this book explores the concept of protective measurement, investigating its broad applications and deep implications. Addressing both physical and philosophical aspects, it covers a diverse range of topics, including experimental possibility of protective measurements, connections with the PBR theorem, and the implications of protective measurements for understanding the nature of quantum reality. Including a clear and concise introduction to standard quantum mechanics, conventional measurements, and the fundamentals of protective measurements, this is a valuable resource for graduate students and researchers interested in the conceptual foundations of quantum mechanics.

Yu. I. Ostrovsky, Mikhail M. Butusov, G. V. Ostrovskaya

John C. Inkson

Aurélien Drezet

Protective measurements which were defined by Aharonov and Vaidman in 1993 played an important role in the discussion about the interpretation of quantum mechanics. In 1999, following an early work by Englert et al., Aharonov et al. wrote an article in which they showed that protective measurements can be used to demonstrate the `surrealism' of Bohmian mechanics. Bohmian mechanics also known as pilot-wave interpretation is certainly the best-known hidden variable interpretation of quantum mechanics. It played a fundamental role in the discovery by Bell of his famous non locality theorem. Therefore, any attacks against pilot-wave interpretation is particularly interesting and instructive to learn something new about the mysterious quantum universe. It is the aim of this chapter to review the debate surrounding protective measurement and pilot-wave and to show if it is possible to reconciliate the different interpretations of the results given in the work by Aharonov et al.