Energy-Constrained LOCC-Assisted Quantum Capacity of the Bosonic Dephasing Channel
We study the LOCC-assisted quantum capacity of a bosonic dephasing channel with energy constraint on the input states. We start our analysis by focusing on the energy-constrained squashed entanglement of the channel, which is an upper bound for the energy-constrained LOCC-assisted quantum capacity....
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-06-01
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| Series: | Entropy |
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| Online Access: | https://www.mdpi.com/1099-4300/25/7/1001 |
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| author | Amir Arqand Laleh Memarzadeh Stefano Mancini |
| author_facet | Amir Arqand Laleh Memarzadeh Stefano Mancini |
| author_sort | Amir Arqand |
| collection | DOAJ |
| description | We study the LOCC-assisted quantum capacity of a bosonic dephasing channel with energy constraint on the input states. We start our analysis by focusing on the energy-constrained squashed entanglement of the channel, which is an upper bound for the energy-constrained LOCC-assisted quantum capacity. As computing energy-constrained squashed entanglement of the channel is challenging due to a double optimization (over the set of density matrices and the isometric extensions of a squashing channel), we first derive an upper bound for it, and then, we discuss how tight that bound is for the energy-constrained LOCC-assisted quantum capacity of the bosonic dephasing channel. In doling so, we prove that the optimal input state is diagonal in the Fock basis. Then, we analyze two explicit examples of squashing channels through which we derive explicit upper and lower bounds for the energy-constrained LOCC-assisted quantum capacity of the bosonic dephasing channel in terms of its quantum capacity with different noise parameters. As the difference between upper and lower bounds becomes smaller by increasing the dephasing parameter, the bounds become tighter. |
| first_indexed | 2024-03-11T01:06:34Z |
| format | Article |
| id | doaj.art-399b1093d3cc454494d216c719e1c933 |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-03-11T01:06:34Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj.art-399b1093d3cc454494d216c719e1c9332023-11-18T19:13:15ZengMDPI AGEntropy1099-43002023-06-01257100110.3390/e25071001Energy-Constrained LOCC-Assisted Quantum Capacity of the Bosonic Dephasing ChannelAmir Arqand0Laleh Memarzadeh1Stefano Mancini2Department of Physics, Sharif University of Technology, Tehran 11365-9161, IranDepartment of Physics, Sharif University of Technology, Tehran 11365-9161, IranSchool of Science & Technology, University of Camerino, I-62032 Camerino, ItalyWe study the LOCC-assisted quantum capacity of a bosonic dephasing channel with energy constraint on the input states. We start our analysis by focusing on the energy-constrained squashed entanglement of the channel, which is an upper bound for the energy-constrained LOCC-assisted quantum capacity. As computing energy-constrained squashed entanglement of the channel is challenging due to a double optimization (over the set of density matrices and the isometric extensions of a squashing channel), we first derive an upper bound for it, and then, we discuss how tight that bound is for the energy-constrained LOCC-assisted quantum capacity of the bosonic dephasing channel. In doling so, we prove that the optimal input state is diagonal in the Fock basis. Then, we analyze two explicit examples of squashing channels through which we derive explicit upper and lower bounds for the energy-constrained LOCC-assisted quantum capacity of the bosonic dephasing channel in terms of its quantum capacity with different noise parameters. As the difference between upper and lower bounds becomes smaller by increasing the dephasing parameter, the bounds become tighter.https://www.mdpi.com/1099-4300/25/7/1001quantum channel mapsquantum capacitiessquashed entanglement |
| spellingShingle | Amir Arqand Laleh Memarzadeh Stefano Mancini Energy-Constrained LOCC-Assisted Quantum Capacity of the Bosonic Dephasing Channel Entropy quantum channel maps quantum capacities squashed entanglement |
| title | Energy-Constrained LOCC-Assisted Quantum Capacity of the Bosonic Dephasing Channel |
| title_full | Energy-Constrained LOCC-Assisted Quantum Capacity of the Bosonic Dephasing Channel |
| title_fullStr | Energy-Constrained LOCC-Assisted Quantum Capacity of the Bosonic Dephasing Channel |
| title_full_unstemmed | Energy-Constrained LOCC-Assisted Quantum Capacity of the Bosonic Dephasing Channel |
| title_short | Energy-Constrained LOCC-Assisted Quantum Capacity of the Bosonic Dephasing Channel |
| title_sort | energy constrained locc assisted quantum capacity of the bosonic dephasing channel |
| topic | quantum channel maps quantum capacities squashed entanglement |
| url | https://www.mdpi.com/1099-4300/25/7/1001 |
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