Violation of space–time Bell-CHSH inequality beyond the Tsirelson bound and quantum cryptography
| Autor: | C. S. Sudheer Kumar |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Discrete mathematics
010308 nuclear & particles physics Space time General Physics and Astronomy CHSH inequality Eavesdropping Context (language use) Quantum Physics Quantum key distribution 01 natural sciences Unitary state 010305 fluids & plasmas Quantum cryptography 0103 physical sciences Quantum Computer Science::Cryptography and Security Mathematics |
| Zdroj: | Pramana. 93 |
| ISSN: | 0973-7111 0304-4289 |
| DOI: | 10.1007/s12043-019-1830-3 |
| Popis: | Here we show that if we insert context-dependent local unitary evolutions into the spatial (i.e. normal) Bell–Clauser–Horne–Shimony–Holt (Bell-CHSH) test, then it is possible to violate the space–time Bell-CHSH inequality maximally (i.e. up to 4). The correct context dependency can be achieved via post-selection. However, this does not contradict the Tsirelson quantum bound ( $$2\sqrt{2}$$ ), because the latter has been derived without taking into consideration the context-dependent unitary evolutions and / or post-selection. As an important application, this leads to a more efficient (in terms of resource (singlets) and classical communication) and more sensitive (to eavesdropping) quantum key distribution (QKD) protocol, compared to Ekert’s and Wigner’s QKD protocols. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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