dorsal/arxiv
View SchemaWhy the Afshar Experiment Does Not Refute Complementarity
| Authors | R. E. Kastner |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0502021 |
| URL | https://arxiv.org/abs/quant-ph/0502021 |
Abstract
A modified version of Young's experiment by Shahriar Afshar demonstrates that, prior to what appears to be a ``which-way'' measurement, an interference pattern exists. Afshar has claimed that this result constitutes a violation of the Principle of Complementarity. This paper discusses the implications of this experiment and considers how Cramer's Transactional Interpretation easily accomodates the result. It is also shown that the Afshar experiment is analogous in key respects to a spin one-half particle prepared as ``spin up along $\bf x$'', subjected to a nondestructive confirmation of that preparation, and post-selected in a specific state of spin along $\bf z$. The terminology ``which-way'' or ``which-slit'' is critiqued; it is argued that this usage by both Afshar and his critics is misleading and has contributed to confusion surrounding the interpretation of the experiment. Nevertheless, it is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post-selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection. In addition, some new inferences about the interpretation of delayed choice experiments are drawn from the analysis.
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"abstract": "A modified version of Young\u0027s experiment by Shahriar Afshar demonstrates\nthat, prior to what appears to be a ``which-way\u0027\u0027 measurement, an interference\npattern exists. Afshar has claimed that this result constitutes a violation of\nthe Principle of Complementarity. This paper discusses the implications of this\nexperiment and considers how Cramer\u0027s Transactional Interpretation easily\naccomodates the result. It is also shown that the Afshar experiment is\nanalogous in key respects to a spin one-half particle prepared as ``spin up\nalong $\\bf x$\u0027\u0027, subjected to a nondestructive confirmation of that\npreparation, and post-selected in a specific state of spin along $\\bf z$.\n The terminology ``which-way\u0027\u0027 or ``which-slit\u0027\u0027 is critiqued; it is argued\nthat this usage by both Afshar and his critics is misleading and has\ncontributed to confusion surrounding the interpretation of the experiment.\nNevertheless, it is concluded that\n Bohr would have had no more problem accounting for the Afshar result than he\nwould in accounting for the aforementioned pre- and post-selection spin\nexperiment, in which the particle\u0027s preparation state is confirmed by a\nnondestructive measurement prior to post-selection. In addition, some new\ninferences about the interpretation of delayed choice experiments are drawn\nfrom the analysis.",
"arxiv_id": "quant-ph/0502021",
"authors": [
"R. E. Kastner"
],
"categories": [
"quant-ph",
"physics.ed-ph",
"physics.pop-ph"
],
"title": "Why the Afshar Experiment Does Not Refute Complementarity",
"url": "https://arxiv.org/abs/quant-ph/0502021"
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