TY - JOUR

T1 - Anomalous weak values via a single photon detection

AU - Rebufello, Enrico

AU - Piacentini, Fabrizio

AU - Avella, Alessio

AU - Souza, Muriel A.de

AU - Gramegna, Marco

AU - Dziewior, Jan

AU - Cohen, Eliahu

AU - Vaidman, Lev

AU - Degiovanni, Ivo Pietro

AU - Genovese, Marco

N1 - Publisher Copyright:
© 2021, The Author(s).

PY - 2021/12

Y1 - 2021/12

N2 - Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100? In 1988 Aharonov, Albert and Vaidman argued that upon pre- and postselection of particular spin states, weakening the coupling of a standard measurement procedure ensures this paradoxical result1. This theoretical prediction, called weak value, was realised in numerous experiments2–9, but its meaning remains very controversial10–19, since its “anomalous” nature, i.e., the possibility to exceed the eigenvalue spectrum, as well as its “quantumness” are debated20–22. We address these questions by presenting the first experiment measuring anomalous weak values with just a single click, without the need for statistical averaging. The measurement uncertainty is significantly smaller than the gap between the measured weak value and the nearest eigenvalue. Beyond clarifying the meaning of weak values, demonstrating their non-statistical, single-particle nature, this result represents a breakthrough in understanding the foundations of quantum measurement, showing unprecedented measurement capability for further applications of weak values to quantum photonics. [Figure not available: see fulltext.]

AB - Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100? In 1988 Aharonov, Albert and Vaidman argued that upon pre- and postselection of particular spin states, weakening the coupling of a standard measurement procedure ensures this paradoxical result1. This theoretical prediction, called weak value, was realised in numerous experiments2–9, but its meaning remains very controversial10–19, since its “anomalous” nature, i.e., the possibility to exceed the eigenvalue spectrum, as well as its “quantumness” are debated20–22. We address these questions by presenting the first experiment measuring anomalous weak values with just a single click, without the need for statistical averaging. The measurement uncertainty is significantly smaller than the gap between the measured weak value and the nearest eigenvalue. Beyond clarifying the meaning of weak values, demonstrating their non-statistical, single-particle nature, this result represents a breakthrough in understanding the foundations of quantum measurement, showing unprecedented measurement capability for further applications of weak values to quantum photonics. [Figure not available: see fulltext.]

UR - http://www.scopus.com/inward/record.url?scp=85106923432&partnerID=8YFLogxK

U2 - 10.1038/s41377-021-00539-0

DO - 10.1038/s41377-021-00539-0

M3 - מזכר

C2 - 34035219

AN - SCOPUS:85106923432

VL - 10

JO - Light: Science and Applications

JF - Light: Science and Applications

SN - 2095-5545

IS - 1

M1 - 106

ER -