Theoretical description and experimental simulation of quantum entanglement near open time-like curves via pseudo-density operators
| Autor: | Marco Gramegna, Chiara Marletto, Marco Genovese, Fabrizio Piacentini, Enrico Rebufello, Vlatko Vedral, Ivo Pietro Degiovanni, Alessio Avella, Salvatore Virzì |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Science General Physics and Astronomy entanglement monogamy FOS: Physical sciences 02 engineering and technology Quantum entanglement General Biochemistry Genetics and Molecular Biology Article Causality (physics) 03 medical and health sciences Theoretical physics Operator (computer programming) quantum optics lcsh:Science Quantum Closed timelike curve Physics Quantum Physics Multidisciplinary pseudo-density operator quantum mechanics open time curves entanglement quantum mechanics quantum optics open time curves pseudo-density operator time travel entanglement monogamy correlation General Chemistry Quantum tomography 021001 nanoscience & nanotechnology 030104 developmental biology Qubit correlation lcsh:Q time travel Quantum cloning 0210 nano-technology entanglement Quantum Physics (quant-ph) |
| Zdroj: | Nature Communications Nature Communications, Vol 10, Iss 1, Pp 1-7 (2019) |
| ISSN: | 2041-1723 |
| Popis: | Closed timelike curves are striking predictions of general relativity allowing for time-travel. They are afflicted by notorious causality issues (e.g. grandfather’s paradox). Quantum models where a qubit travels back in time solve these problems, at the cost of violating quantum theory’s linearity—leading e.g. to universal quantum cloning. Interestingly, linearity is violated even by open timelike curves (OTCs), where the qubit does not interact with its past copy, but is initially entangled with another qubit. Non-linear dynamics is needed to avoid violating entanglement monogamy. Here we propose an alternative approach to OTCs, allowing for monogamy violations. Specifically, we describe the qubit in the OTC via a pseudo-density operator—a unified descriptor of both temporal and spatial correlations. We also simulate the monogamy violation with polarization-entangled photons, providing a pseudo-density operator quantum tomography. Remarkably, our proposal applies to any space-time correlations violating entanglement monogamy, such as those arising in black holes. Description of a qubit following an open time-like curve usually incurs into conceptual problems such as violation of entanglement monogamy. Here, the authors show how to use the formalism of pseudo-density operators to describe such a process, showing a proof-of-principle experimental simulation. |
| Databáze: | OpenAIRE |
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