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Joint measurability of generalized measurements implies classicality
Roope Uola1, Tobias Moroder1, Otfried Gühne1
1Naturwissenschaftlich-Technische Fakultät, Universität Siegen, Walter-Flex-Strasse 3, 57068 Siegen, Germany.
Physical Review Letters
|November 1, 2014
Summary
Quantum mechanics features non-simultaneous measurements. Generalized measurements that are not jointly measurable exhibit nonclassical behavior and can be used for quantum steering, defining quantum features.
Area of Science:
- Quantum mechanics
- Quantum information theory
Background:
- Quantum mechanics exhibits non-simultaneous measurement properties, leading to phenomena like complementarity and uncertainty relations.
- Characterizing generalized quantum measurements for classical vs. quantum behavior is challenging.
Purpose of the Study:
- To establish a definitive criterion for identifying nonclassical behavior in generalized quantum measurements.
- To link the concept of joint measurability to quantum steering.
Main Methods:
- Proving that a set of generalized measurements failing joint measurability can perform quantum steering.
- Utilizing established results from joint measurability and quantum steering.
Main Results:
- A set of generalized measurements is nonclassical if and only if it lacks joint measurability.
- This nonclassicality is demonstrated through the task of quantum steering.
Conclusions:
- Joint measurability serves as the proper criterion to characterize quantum behavior in measurements.
- The established equivalence enables the derivation of new steering inequalities and joint measurability criteria.
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