Direct estimation of quantum coherence by collective measurements
| Autor: | Alexander Streltsov, Jun-Feng Tang, Guang-Can Guo, Guo-Yong Xiang, Zhibo Hou, Yuan Yuan, Chuan-Feng Li |
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| Rok vydání: | 2020 |
| Předmět: |
Quantum Physics
Photon Computer Networks and Communications Computer science FOS: Physical sciences Statistical and Nonlinear Physics Coherence (statistics) lcsh:QC1-999 lcsh:QA75.5-76.95 Quantum biology Computational Theory and Mathematics Quantum state Qubit Computer Science (miscellaneous) lcsh:Electronic computers. Computer science Statistical physics Qutrit Quantum Physics (quant-ph) Quantum lcsh:Physics Quantum computer |
| Zdroj: | npj Quantum Information, Vol 6, Iss 1, Pp 1-5 (2020) |
| ISSN: | 2056-6387 |
| DOI: | 10.1038/s41534-020-0280-6 |
| Popis: | The recently established resource theory of quantum coherence allows for a quantitative understanding of the superposition principle, with applications reaching from quantum computing to quantum biology. While different quantifiers of coherence have been proposed in the literature, their efficient estimation in today's experiments remains a challenge. Here, we introduce a collective measurement scheme for estimating the amount of coherence in quantum states, which requires entangled measurements on two copies of the state. As we show by numerical simulations, our scheme outperforms other estimation methods based on tomography or adaptive measurements, leading to a higher precision in a large parameter range for estimating established coherence quantifiers of qubit and qutrit states. We show that our method is accessible with today's technology by implementing it experimentally with photons, finding a good agreement between experiment and theory. Comment: 8 pages, 5 figures |
| Databáze: | OpenAIRE |
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