Leggett不等式是对允许某些类型非定域性的二体关联的约束。对更多体的情况是否也可以得到这样的约束？我们对三体的情况找到了新的不等式，可以用来检验量子力学和非定域实在论之间的相容性。对某些测量装置，GHZ，W和任意三量子比特纯态违背了不等式。我们的不等式比文献(arXiv:1111.4119v1)中已有的不等式强。这些实验上可实现的不等式能推广到n体，这可以更好地解释多体情况下的非定域关联，也可以应用在超越标准量子密钥分发方案的密码密钥分发。
KHAN Abdul Sattar
,
杨马成
,
乔从丰
. 三体Leggett型非定域性能被测试吗？[J]. 中国科学院大学学报, 2023
, 40(3)
: 297
-302
.
DOI: 10.7523/j.ucas.2021.0087
The Leggett inequality is a constraint on the bipartite correlation that admits certain types of nonlocalities. Could such constraints be obtained for more parties? Here in search for the answer we found new inequalities for three parties which could be used to check the compatibility between quantum mechanics and nonlocal realism. For certain measurement settings violations are found for GHZ, W and an arbitrary three-qubit pure states. Our inequalities are stronger than the existing inequality in literature (arXiv:1111. 4119v1). These experimentally realizable inequalities, generalization to n-parties possible, could better our explanations for nonlocal correlations in multiparty case, along with some applications in cryptographic key distribution beyond the standard quantum key distribution schemes.
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