A scheme for performing strong and weak sequential measurements of non-commuting observables

Quantum Studies: Mathematics and Foundations - Tập 4 - Trang 13-27 - 2016
Aharon Brodutch1, Eliahu Cohen2,3
1Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada
2School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
3H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK

Tóm tắt

Quantum systems usually travel a multitude of different paths when evolving through time from an initial to a final state. In general, the possible paths will depend on the future and past boundary conditions, as well as the system’s dynamics. We present a gedanken experiment where a single system apparently follows mutually exclusive paths simultaneously, each with probability one, depending on which measurement was performed. This experiment involves the measurement of observables that do not correspond to Hermitian operators. Our main result is a scheme for measuring these operators. The scheme is based on the erasure protocol [Brodutch and Cohen (Phys. Rev. Lett. 116:070404, 2016)] and allows a wide range of sequential measurements at both the weak and strong limits. At the weak limit the back action of the measurement cannot be used to account for the surprising behaviour and the resulting weak values provide a consistent yet strange account of the system’s past.

Tài liệu tham khảo

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