Efficient separation of quantum from classical correlations for mixed states with a fixed charge
Entanglement is the key resource for quantum technologies and is at the root of exciting many-body phenomena. However, quantifying the entanglement between two parts of a real-world quantum system is challenging when it interacts with its environment, as the latter mixes cross-boundary classical wit...
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| Format: | Article |
| Language: | English |
| Published: |
Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften
2023-03-01
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| Series: | Quantum |
| Online Access: | https://quantum-journal.org/papers/q-2023-03-20-954/pdf/ |
| _version_ | 1797867139821993984 |
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| author | Christian Carisch Oded Zilberberg |
| author_facet | Christian Carisch Oded Zilberberg |
| author_sort | Christian Carisch |
| collection | DOAJ |
| description | Entanglement is the key resource for quantum technologies and is at the root of exciting many-body phenomena. However, quantifying the entanglement between two parts of a real-world quantum system is challenging when it interacts with its environment, as the latter mixes cross-boundary classical with quantum correlations. Here, we efficiently quantify quantum correlations in such realistic open systems using the operator space entanglement spectrum of a mixed state. If the system possesses a fixed charge, we show that a subset of the spectral values encode coherence between different cross-boundary charge configurations. The sum over these values, which we call "configuration coherence", can be used as a quantifier for cross-boundary coherence. Crucially, we prove that for purity non-increasing maps, e.g., Lindblad-type evolutions with Hermitian jump operators, the configuration coherence is an entanglement measure. Moreover, it can be efficiently computed using a tensor network representation of the state's density matrix. We showcase the configuration coherence for spinless particles moving on a chain in presence of dephasing. Our approach can quantify coherence and entanglement in a broad range of systems and motivates efficient entanglement detection. |
| first_indexed | 2024-04-09T23:35:32Z |
| format | Article |
| id | doaj.art-cd95eba9be41487aace4ebee137b86a8 |
| institution | Directory Open Access Journal |
| issn | 2521-327X |
| language | English |
| last_indexed | 2024-04-09T23:35:32Z |
| publishDate | 2023-03-01 |
| publisher | Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften |
| record_format | Article |
| series | Quantum |
| spelling | doaj.art-cd95eba9be41487aace4ebee137b86a82023-03-20T13:22:44ZengVerein zur Förderung des Open Access Publizierens in den QuantenwissenschaftenQuantum2521-327X2023-03-01795410.22331/q-2023-03-20-95410.22331/q-2023-03-20-954Efficient separation of quantum from classical correlations for mixed states with a fixed chargeChristian CarischOded ZilberbergEntanglement is the key resource for quantum technologies and is at the root of exciting many-body phenomena. However, quantifying the entanglement between two parts of a real-world quantum system is challenging when it interacts with its environment, as the latter mixes cross-boundary classical with quantum correlations. Here, we efficiently quantify quantum correlations in such realistic open systems using the operator space entanglement spectrum of a mixed state. If the system possesses a fixed charge, we show that a subset of the spectral values encode coherence between different cross-boundary charge configurations. The sum over these values, which we call "configuration coherence", can be used as a quantifier for cross-boundary coherence. Crucially, we prove that for purity non-increasing maps, e.g., Lindblad-type evolutions with Hermitian jump operators, the configuration coherence is an entanglement measure. Moreover, it can be efficiently computed using a tensor network representation of the state's density matrix. We showcase the configuration coherence for spinless particles moving on a chain in presence of dephasing. Our approach can quantify coherence and entanglement in a broad range of systems and motivates efficient entanglement detection.https://quantum-journal.org/papers/q-2023-03-20-954/pdf/ |
| spellingShingle | Christian Carisch Oded Zilberberg Efficient separation of quantum from classical correlations for mixed states with a fixed charge Quantum |
| title | Efficient separation of quantum from classical correlations for mixed states with a fixed charge |
| title_full | Efficient separation of quantum from classical correlations for mixed states with a fixed charge |
| title_fullStr | Efficient separation of quantum from classical correlations for mixed states with a fixed charge |
| title_full_unstemmed | Efficient separation of quantum from classical correlations for mixed states with a fixed charge |
| title_short | Efficient separation of quantum from classical correlations for mixed states with a fixed charge |
| title_sort | efficient separation of quantum from classical correlations for mixed states with a fixed charge |
| url | https://quantum-journal.org/papers/q-2023-03-20-954/pdf/ |
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