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arXiv · 1304.1640

Null weak values in multi-level systems

Oded Zilberberg·Alessandro Romito·Yuval Gefen
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Abstract

A two-step measurement protocol of a quantum system, known as weak value (WV), has been introduced more than two decades ago by Aharonov et al. [1], and has since been studied in various contexts. Here we discuss another two-step measurement protocol which we dub null weak value (NWV). The protocol consists of a partial-collapse measurement followed by quantum manipulation on the system and finally a strong measurement. The first step is a strong measurement which takes place with small probability. The second strong measurement is used as postselection on the outcome of the earlier step. Not being measured in the partial-collapse stage (null outcome) leads to a non-trivial correlation between the two measurements. The NVW protocol, first defined for a two-level system [2], is generalized to a multi-level system, and compared to the standard-WV protocol.

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Oded Zilberberg, Alessandro Romito, Yuval Gefen. 2013-04-05. Null weak values in multi-level systems. https://doi.org/10.1088/0031-8949%2F2012%2Ft151%2F014014

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