Entanglement, scaling, and the meaning of the wave function in protective measurement

Maximilian Schlosshauer and Tangereen V. B. Claringbold (University of Portland)

We examine the entanglement and state disturbance arising in a protective measurement and argue that these inescapable effects doom the claim that protective measurement establishes the reality of the wave function. An additional challenge to this claim results from the exponential number of protective measurements required to reconstruct multi-qubit states. We suggest that the failure of protective measurement to settle the question of the meaning of the wave function is entirely expected, for protective measurement is but an application of the standard quantum formalism, and none of the hard foundational questions can ever be settled in this way. Full text

To appear in “Protective Measurements and Quantum Reality: Toward a New Understanding of Quantum Mechanics,” edited by S. Gao (Cambridge University Press, Cambridge, 2014).

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