Entanglement in prepare-and-measure scenarios: many questions, a few answers
Entanglement and quantum communication are paradigmatic resources in quantum information science leading to correlations between systems that have no classical analogue. Correlations due to entanglement when communication is absent have for long been studied in Bell scenarios. Correlations due to qu...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/ac724a |
| _version_ | 1827871072465190912 |
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| author | Jef Pauwels Armin Tavakoli Erik Woodhead Stefano Pironio |
| author_facet | Jef Pauwels Armin Tavakoli Erik Woodhead Stefano Pironio |
| author_sort | Jef Pauwels |
| collection | DOAJ |
| description | Entanglement and quantum communication are paradigmatic resources in quantum information science leading to correlations between systems that have no classical analogue. Correlations due to entanglement when communication is absent have for long been studied in Bell scenarios. Correlations due to quantum communication when entanglement is absent have been studied extensively in prepare-and-measure (PM) scenarios in the last decade. Here, we set out to understand and investigate correlations in scenarios that involve both entanglement and communication, focussing on entanglement-assisted (EA) PM scenarios. In a recent companion paper (arXiv: 2103.10748 ), we investigated correlations based on unrestricted entanglement. Here, our focus is on scenarios with restricted entanglement. We establish several elementary relations between standard classical and quantum communication and their EA counterparts. In particular, while it was already known that bits or qubits assisted by two-qubit entanglement between the sender and receiver constitute a stronger resource than bare bits or qubits, we show that higher-dimensional entanglement further enhance the power of bits or qubits. We also provide a characterisation of generalised dense coding protocols, a natural subset of EA quantum communication protocols, finding that they can be understood as standard quantum communication protocols in real-valued Hilbert space. Though such dense coding protocols can convey up to two bits of information, we provide evidence, perhaps counter-intuitively, that resources with a small information capacity, such as a bare qutrits, can sometimes produce stronger correlations. Along the way we leave several conjectures and conclude with a list of interesting open problems. |
| first_indexed | 2024-03-12T16:04:48Z |
| format | Article |
| id | doaj.art-a5bf42a794604adabedca10fa140f2f7 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:04:48Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-a5bf42a794604adabedca10fa140f2f72023-08-09T14:25:00ZengIOP PublishingNew Journal of Physics1367-26302022-01-0124606301510.1088/1367-2630/ac724aEntanglement in prepare-and-measure scenarios: many questions, a few answersJef Pauwels0https://orcid.org/0000-0003-4440-7411Armin Tavakoli1https://orcid.org/0000-0001-9136-7411Erik Woodhead2https://orcid.org/0000-0001-7696-4461Stefano Pironio3https://orcid.org/0000-0002-7196-2608Laboratoire d’Information Quantique, Université libre de Bruxelles (ULB) , BelgiumInstitute for Quantum Optics and Quantum Information-IQOQI Vienna, Austrian Academy of Sciences , Boltzmanngasse 3, 1090 Vienna, Austria; Institute for Atomic and Subatomic Physics, Vienna University of Technology , 1020 Vienna, AustriaLaboratoire d’Information Quantique, Université libre de Bruxelles (ULB) , BelgiumLaboratoire d’Information Quantique, Université libre de Bruxelles (ULB) , BelgiumEntanglement and quantum communication are paradigmatic resources in quantum information science leading to correlations between systems that have no classical analogue. Correlations due to entanglement when communication is absent have for long been studied in Bell scenarios. Correlations due to quantum communication when entanglement is absent have been studied extensively in prepare-and-measure (PM) scenarios in the last decade. Here, we set out to understand and investigate correlations in scenarios that involve both entanglement and communication, focussing on entanglement-assisted (EA) PM scenarios. In a recent companion paper (arXiv: 2103.10748 ), we investigated correlations based on unrestricted entanglement. Here, our focus is on scenarios with restricted entanglement. We establish several elementary relations between standard classical and quantum communication and their EA counterparts. In particular, while it was already known that bits or qubits assisted by two-qubit entanglement between the sender and receiver constitute a stronger resource than bare bits or qubits, we show that higher-dimensional entanglement further enhance the power of bits or qubits. We also provide a characterisation of generalised dense coding protocols, a natural subset of EA quantum communication protocols, finding that they can be understood as standard quantum communication protocols in real-valued Hilbert space. Though such dense coding protocols can convey up to two bits of information, we provide evidence, perhaps counter-intuitively, that resources with a small information capacity, such as a bare qutrits, can sometimes produce stronger correlations. Along the way we leave several conjectures and conclude with a list of interesting open problems.https://doi.org/10.1088/1367-2630/ac724aentanglementcorrelationsquantum communication |
| spellingShingle | Jef Pauwels Armin Tavakoli Erik Woodhead Stefano Pironio Entanglement in prepare-and-measure scenarios: many questions, a few answers New Journal of Physics entanglement correlations quantum communication |
| title | Entanglement in prepare-and-measure scenarios: many questions, a few answers |
| title_full | Entanglement in prepare-and-measure scenarios: many questions, a few answers |
| title_fullStr | Entanglement in prepare-and-measure scenarios: many questions, a few answers |
| title_full_unstemmed | Entanglement in prepare-and-measure scenarios: many questions, a few answers |
| title_short | Entanglement in prepare-and-measure scenarios: many questions, a few answers |
| title_sort | entanglement in prepare and measure scenarios many questions a few answers |
| topic | entanglement correlations quantum communication |
| url | https://doi.org/10.1088/1367-2630/ac724a |
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