Activation and superactivation of single-mode Gaussian quantum channels
Activation of quantum capacity is a surprising phenomenon according to which the quantum capacity of a certain channel may increase by combining it with another channel with zero quantum capacity. Superactivation describes an even more particular occurrence, in which both channels have zero quantum...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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American Physical Society
2019
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| Online Access: | https://hdl.handle.net/1721.1/121249 |
| _version_ | 1826190754994716672 |
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| author | Lim, Youngrong Takagi, Ryuji Adesso, Gerardo Lee, Soojoon |
| author2 | Massachusetts Institute of Technology. Center for Theoretical Physics |
| author_facet | Massachusetts Institute of Technology. Center for Theoretical Physics Lim, Youngrong Takagi, Ryuji Adesso, Gerardo Lee, Soojoon |
| author_sort | Lim, Youngrong |
| collection | MIT |
| description | Activation of quantum capacity is a surprising phenomenon according to which the quantum capacity of a certain channel may increase by combining it with another channel with zero quantum capacity. Superactivation describes an even more particular occurrence, in which both channels have zero quantum capacity, but their composition has a nonvanishing one. We investigate these effects for all single-mode phase-insensitive Gaussian channels, which include thermal attenuators and amplifiers, assisted by a two-mode positive-partial-transpose channel. Our result shows that activation phenomena are special but not uncommon. We can reveal superactivation in a broad range of thermal attenuator channels, even when the transmissivity is quite low, or the thermal noise is high. This means that we can transmit quantum information reliably through very noisy Gaussian channels with the help of another Gaussian channel, whose quantum capacity is also zero. We further show that no superactivation is possible for entanglement-breaking Gaussian channels in physically relevant circumstances by proving the nonactivation property of the coherent information of bosonic entanglement-breaking channels with finite input energy. |
| first_indexed | 2024-09-23T08:45:11Z |
| format | Article |
| id | mit-1721.1/121249 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:45:11Z |
| publishDate | 2019 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/1212492022-09-30T11:00:39Z Activation and superactivation of single-mode Gaussian quantum channels Lim, Youngrong Takagi, Ryuji Adesso, Gerardo Lee, Soojoon Massachusetts Institute of Technology. Center for Theoretical Physics Massachusetts Institute of Technology. Department of Physics Activation of quantum capacity is a surprising phenomenon according to which the quantum capacity of a certain channel may increase by combining it with another channel with zero quantum capacity. Superactivation describes an even more particular occurrence, in which both channels have zero quantum capacity, but their composition has a nonvanishing one. We investigate these effects for all single-mode phase-insensitive Gaussian channels, which include thermal attenuators and amplifiers, assisted by a two-mode positive-partial-transpose channel. Our result shows that activation phenomena are special but not uncommon. We can reveal superactivation in a broad range of thermal attenuator channels, even when the transmissivity is quite low, or the thermal noise is high. This means that we can transmit quantum information reliably through very noisy Gaussian channels with the help of another Gaussian channel, whose quantum capacity is also zero. We further show that no superactivation is possible for entanglement-breaking Gaussian channels in physically relevant circumstances by proving the nonactivation property of the coherent information of bosonic entanglement-breaking channels with finite input energy. 2019-06-11T20:10:17Z 2019-06-11T20:10:17Z 2019-03 2019-01 2019-03-25T18:00:09Z Article http://purl.org/eprint/type/JournalArticle 2469-9926 2469-9934 https://hdl.handle.net/1721.1/121249 Lim, Youngrong et al. "Activation and superactivation of single-mode Gaussian quantum channels." Physical Review A 99, 3 (March 2019): 032337 © 2019 American Physical Society en http://dx.doi.org/10.1103/PhysRevA.99.032337 Physical Review A Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Physical Society application/pdf American Physical Society American Physical Society |
| spellingShingle | Lim, Youngrong Takagi, Ryuji Adesso, Gerardo Lee, Soojoon Activation and superactivation of single-mode Gaussian quantum channels |
| title | Activation and superactivation of single-mode Gaussian quantum channels |
| title_full | Activation and superactivation of single-mode Gaussian quantum channels |
| title_fullStr | Activation and superactivation of single-mode Gaussian quantum channels |
| title_full_unstemmed | Activation and superactivation of single-mode Gaussian quantum channels |
| title_short | Activation and superactivation of single-mode Gaussian quantum channels |
| title_sort | activation and superactivation of single mode gaussian quantum channels |
| url | https://hdl.handle.net/1721.1/121249 |
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