The Experts below are selected from a list of 22623 Experts worldwide ranked by ideXlab platform
Uttam Singh - One of the best experts on this subject based on the ideXlab platform.
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maximum relative entropy of coherence an operational coherence measure
Physical Review Letters, 2017Co-Authors: Shaoming Fei, Uttam Singh, Arun Kumar PatiAbstract:The operational characterization of quantum coherence is the cornerstone in the development of the resource theory of coherence. We introduce a new coherence quantifier based on maximum relative entropy. We prove that the maximum relative entropy of coherence is directly related to the maximum overlap with maximally coherent states under a particular class of operations, which provides an operational interpretation of the maximum relative entropy of coherence. Moreover, we show that, for any coherent state, there are examples of subchannel discrimination problems such that this coherent state allows for a higher probability of successfully discriminating subchannels than that of all incoherent states. This advantage of coherent states in subchannel discrimination can be exactly characterized by the maximum relative entropy of coherence. By introducing a suitable smooth maximum relative entropy of coherence, we prove that the smooth maximum relative entropy of coherence provides a lower bound of one-shot coherence cost, and the maximum relative entropy of coherence is equivalent to the relative entropy of coherence in the asymptotic limit. Similar to the maximum relative entropy of coherence, the minimum relative entropy of coherence has also been investigated. We show that the minimum relative entropy of coherence provides an upper bound of one-shot coherence distillation, and in the asymptotic limit the minimum relative entropy of coherence is equivalent to the relative entropy of coherence.
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max relative entropy of coherence an operational coherence measure
Physical Review Letters, 2017Co-Authors: Kaifeng Bu, Arun Kumar Pati, Uttam Singh, Junde WuAbstract:The operational characterization of quantum coherence is the corner stone in the development of resource theory of coherence. We introduce a new coherence quantifier based on max-relative entropy. We prove that max-relative entropy of coherence is directly related to the maximum overlap with maximally coherent states under a particular class of operations, which provides an operational interpretation of max-relative entropy of coherence. Moreover, we show that, for any coherent state, there are examples of subchannel discrimination problems such that this coherent state allows for a higher probability of successfully discriminating subchannels than that of all incoherent states. This advantage of coherent states in subchannel discrimination can be exactly characterized by the max-relative entropy of coherence. By introducing suitable smooth max-relative entropy of coherence, we prove that the smooth max-relative entropy of coherence provides a lower bound of one-shot coherence cost, and the max-relative entropy of coherence is equivalent to the relative entropy of coherence in asymptotic limit. Similar to max-relative entropy of coherence, min-relative entropy of coherence has also been investigated. We show that the min-relative entropy of coherence provides an upper bound of one-shot coherence distillation, and in asymptotic limit the min-relative entropy of coherence is equivalent to the relative entropy of coherence.
Arun Kumar Pati - One of the best experts on this subject based on the ideXlab platform.
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maximum relative entropy of coherence an operational coherence measure
Physical Review Letters, 2017Co-Authors: Shaoming Fei, Uttam Singh, Arun Kumar PatiAbstract:The operational characterization of quantum coherence is the cornerstone in the development of the resource theory of coherence. We introduce a new coherence quantifier based on maximum relative entropy. We prove that the maximum relative entropy of coherence is directly related to the maximum overlap with maximally coherent states under a particular class of operations, which provides an operational interpretation of the maximum relative entropy of coherence. Moreover, we show that, for any coherent state, there are examples of subchannel discrimination problems such that this coherent state allows for a higher probability of successfully discriminating subchannels than that of all incoherent states. This advantage of coherent states in subchannel discrimination can be exactly characterized by the maximum relative entropy of coherence. By introducing a suitable smooth maximum relative entropy of coherence, we prove that the smooth maximum relative entropy of coherence provides a lower bound of one-shot coherence cost, and the maximum relative entropy of coherence is equivalent to the relative entropy of coherence in the asymptotic limit. Similar to the maximum relative entropy of coherence, the minimum relative entropy of coherence has also been investigated. We show that the minimum relative entropy of coherence provides an upper bound of one-shot coherence distillation, and in the asymptotic limit the minimum relative entropy of coherence is equivalent to the relative entropy of coherence.
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max relative entropy of coherence an operational coherence measure
Physical Review Letters, 2017Co-Authors: Kaifeng Bu, Arun Kumar Pati, Uttam Singh, Junde WuAbstract:The operational characterization of quantum coherence is the corner stone in the development of resource theory of coherence. We introduce a new coherence quantifier based on max-relative entropy. We prove that max-relative entropy of coherence is directly related to the maximum overlap with maximally coherent states under a particular class of operations, which provides an operational interpretation of max-relative entropy of coherence. Moreover, we show that, for any coherent state, there are examples of subchannel discrimination problems such that this coherent state allows for a higher probability of successfully discriminating subchannels than that of all incoherent states. This advantage of coherent states in subchannel discrimination can be exactly characterized by the max-relative entropy of coherence. By introducing suitable smooth max-relative entropy of coherence, we prove that the smooth max-relative entropy of coherence provides a lower bound of one-shot coherence cost, and the max-relative entropy of coherence is equivalent to the relative entropy of coherence in asymptotic limit. Similar to max-relative entropy of coherence, min-relative entropy of coherence has also been investigated. We show that the min-relative entropy of coherence provides an upper bound of one-shot coherence distillation, and in asymptotic limit the min-relative entropy of coherence is equivalent to the relative entropy of coherence.
Bahaa E A Saleh - One of the best experts on this subject based on the ideXlab platform.
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optical Coherency matrix tomography
Scientific Reports, 2015Co-Authors: Kumel H Kagalwala, Hasan E Kondakci, Ayman F Abouraddy, Bahaa E A SalehAbstract:The coherence of an optical beam having multiple degrees of freedom (DoFs) is described by a Coherency matrix G spanning these DoFs. This optical Coherency matrix has not been measured in its entirety to date—even in the simplest case of two binary DoFs where G is a 4 × 4 matrix. We establish a methodical yet versatile approach—optical Coherency matrix tomography—for reconstructing G that exploits the analogy between this problem in classical optics and that of tomographically reconstructing the density matrix associated with multipartite quantum states in quantum information science. Here G is reconstructed from a minimal set of linearly independent measurements, each a cascade of projective measurements for each DoF. We report the first experimental measurements of the 4 × 4 Coherency matrix G associated with an electromagnetic beam in which polarization and a spatial DoF are relevant, ranging from the traditional two-point Young’s double slit to spatial parity and orbital angular momentum modes.
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two point optical Coherency matrix tomography
Optics Letters, 2014Co-Authors: Ayman F Abouraddy, Kumel H Kagalwala, Bahaa E A SalehAbstract:The two-point coherence of an electromagnetic field is represented completely by a 4×4 Coherency matrix G that encodes the joint polarization–spatial-field correlations. Here, we describe a systematic sequence of cascaded spatial and polarization projective measurements that are sufficient to tomographically reconstruct G—a task that, to the best of our knowledge, has not yet been realized. Our approach benefits from the correspondence between this reconstruction problem in classical optics and that of quantum state tomography for two-photon states in quantum optics. Identifying G uniquely determines all the measurable correlation characteristics of the field and, thus, lifts ambiguities that arise from reliance on traditional scalar descriptors, especially when the field’s degrees of freedom are correlated or classically entangled.
Youliang Yan - One of the best experts on this subject based on the ideXlab platform.
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rhymes a shared virtual memory system for non coherent tiled many core architectures
International Conference on Parallel and Distributed Systems, 2014Co-Authors: King Tin Lam, Jinghao Shi, Dominic Hung, Choli Wang, Zhiquan Lai, Wangbin Zhu, Youliang YanAbstract:The rising core count per processor is pushing chip complexity to a level that hardware-based cache Coherency protocols become too hard and costly to scale someday. We need new designs of many-core hardware and software other than traditional technologies to keep up with the ever-increasing scalability demands. A cluster-on-chip architecture, as exemplified by the Intel Single-chip Cloud Computer (SCC), promotes a software-oriented approach instead of hardware support to implementing shared memory coherence. This paper presents a shared virtual memory (SVM) system, dubbed Rhymes, tailored to new processor kinds of non-coherent and hybrid memory architectures. Rhymes features a two-way cache coherence protocol to enforce release consistency for pages allocated in shared physical memory (SPM) and scope consistency for pages in percore private memory. It also supports page remapping on a percore basis to boost data locality. We implement and test Rhymes on the SCC port of the Barrelfish OS. Experimental results show that our SVM outperforms the pure SPM approach used by Intel's software managed coherence (SMC) library by up to 12 times through improved cache utilization for applications with strong data reuse patterns.
Muhammad Shahbaz - One of the best experts on this subject based on the ideXlab platform.
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a multiple and partial wavelet analysis of the oil price inflation exchange rate and economic growth nexus in saudi arabia
Emerging Markets Finance and Trade, 2018Co-Authors: Chaker Aloui, Besma Hkiri, Shawkat Hammoudeh, Muhammad ShahbazAbstract:This article provides a fresh insight into the dynamic nexus between oil prices, the Saudi/US dollar exchange rate, inflation, and output growth rate in Saudi Arabia’ economy, using novel Morlet’ wavelet methods. Specifically, it implements various tools of methodology: the continuous wavelet power spectrum, the cross-wavelet power spectrum, the wavelet Coherency, the multiple and the partial wavelet coherence to the annual sample period 1969–2014. Our results unveil that the relationships among the variables evolve through time and frequency. From the time-domain view, we show strong but non-homogenous linkages between the four variables. From the frequency-domain view, we uncover significant wavelet coherences and strong lead-lag relationships. From an economic view, the wavelet analysis shows that Saudi economy is still exposed to several global risk factors, which are mainly related to the oil market volatility, and the pegging of the local currency to the US dollar. Such risk factors strongly and negatively affect the real economic growth, exert more pressure on inflation, and substantially limit the freedom to pursue an independent monetary policy.
