Semitransparency in interaction-free measurements

Abstract

We discuss the effect of semitransparency in a quantum-Zeno-like interaction-free measurement setup, a quantum-physics based approach that might significantly reduce sample damage in imaging and microscopy. With an emphasis on applications in electron microscopy, we simulate the behavior of probe particles in an interaction-free measurement setup with semitransparent samples, and we show that the transparency of a sample can be measured in such a setup. However, such a measurement is not possible without losing (i.e., absorbing or scattering) probe particles in general, which causes sample damage. We show how the amount of lost particles can be minimized by adjusting the number of round trips through the setup, and we explicitly calculate the amount of lost particles in measurements which either aim at distinguishing two transparencies or at measuring an unknown transparency precisely. We also discuss the effect of the sample causing phase shifts in interaction-free measurements. Comparing the resulting loss of probe particles with a classical measurement of transparency, we find that interaction-free measurements only provide a benefit in two cases: first, if two semitransparent samples with a high contrast are to be distinguished, interaction-free measurements lose less particles than classical measurements by a factor that increases with the contrast. This implies that interaction-free measurements with zero loss are possible if one of the samples is perfectly transparent. A second case where interaction-free measurements outperform classical measurements is if three conditions are met: the particle source exhibits Poissonian number statistics, the number of lost particles cannot be measured, and the transparency is larger than approximately 1/2. In all other cases, interaction-free measurements lose as many probe particles as classical measurements or more.

11 pages, 10 figures

References in corpus (8)

• Quantum Mechanical Interaction-Free Measurements
• High-efficiency quantum interrogation measurements via the quantum Zeno effect
• Experiment on Interaction-Free Measurement in Neutron Interferometry
• "Interaction-free" discrimination between semi-transparent objects
• Possible use of a Cooper-pair box for low-dose electron microscopy
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Cited by in corpus (7)

• Transmission Electron Microscopy at the Quantum Limit
• Reduced damage in electron microscopy by using interaction-free measurement and conditional re-illumination
• Interaction-free imaging of multi-pixel objects
• Misinference of interaction-free measurement from a classical system
• Interaction-free measurement study as a quantum channel discrimination problem
• Resilient quantum electron microscopy
• Interaction-Free Measurements of Optical Semitransparent Objects