Protective Measurements

Abstract

Protective measurements yield properties of the quantum state of a single quantum system without affecting the quantum state. A protective measurement involves adiabatic coupling to the measuring device together with a procedure to protect the state from changing. For nondegenerate energy eigenstates the protection is provided by the system itself. In this case it is actually possible to measure the Schrödinger wave via measurements on a single system. This fact provides an argument in favor of associating physical reality with a quantum state of a single system, challenging the usual ensemble interpretation. We also believe that the complete description of a quantum system requires a two-state vector formalism involving (in addition to the usual one)a future quantum state evolving backwards in time. Protective measurements testing the two-state vector reality are constructed.

21 pages, 1 figure

References in corpus (6)

• Measurement of the Schrodinger wave of a single particle
• The Reality and Measurement of the Wavefunction
• Measurements, errors, and negative kinetic energy
• How to protect the interpretation of the wave function against protective measurements
• Adiabatic Measurements on Metastable Systems
• Realistic experiments for measuring the wave function of a single particle

Cited by in corpus (11)

• Weak-Measurement Elements of Reality
• On a Time Symmetric Formulation of Quantum Mechanics
• Adiabatic Measurements on Metastable Systems
• Quantum Computation Based on Retarded and Advanced Propagation
• Comment on ``Protective measurements of the wave function of a single squeezed harmonic-oscillator state''
• The Wave Function and Quantum Reality
• Protective Measurements and the Reality of the Wave Function
• On Historical Background to the Ontic Breakthrough.I Polemic Defense of Quantum Reality
• Weak measurements, non-classicality and negative probability
• Emergence of Weak Values
• A no-go result for QBism