2012年1月，量子物理与量子信息研究部郁司夏教授研究组在PHYSICAL REVIEW LETTERS上发表题为State-Independent Proof of Kochen-Specker Theorem with 13 Rays的论文。

Source: PHYSICAL REVIEW LETTERS Volume: 108 Issue: 3 Article Number: 030402 DOI: 10.1103/PhysRevLett.108.030402 Published: JAN 18 2012
Yu, SX (Yu, Sixia)1,2,3,4; Oh, CH (Oh, C. H.)1,2
Addresses:
1. Natl Univ Singapore, Ctr Quantum technol, Singapore 117543, Singapore
2. Natl Univ Singapore, Dept Phys, Singapore 117543, Singapore
3. Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei 230026, Anhui, Peoples R China
4. Univ Sci & Technol China, Dept Modern Phys, Hefei 230026, Anhui, Peoples R China

Reprint Address: Yu, SX (reprint author), Natl Univ Singapore, Ctr Quantum technol, 3 Sci Dr 2, Singapore 117543, Singapore

Abstract: Quantum contextuality, as proved by Kochen and Specker, and also by Bell, should manifest itself in any state in any system with more than two distinguishable states and recently has been experimentally verified. However, for the simplest system capable of exhibiting contextuality, a qutrit, the quantum contextuality is verified only state dependently in experiment because too many (at least 31) observables are involved in all the known state-independent tests. Here we report an experimentally testable inequality involving only 13 observables that is satisfied by all noncontextual realistic models while being violated by all qutrit states. Thus our inequality facilitates a state-independent test of the quantum contextuality for an indivisible quantum system. We also provide a record-breaking state-independent proof of the Kochen-Specker theorem with 13 directions determined by 26 points on the surface of a magic cube.