Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 10 of 10 for “"von Neumann entropy"”.
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Higher-order moments of entanglement estimators over generic state ensembles
… by the entanglement indicators including the von Neumann entropy and entanglement capacity. This work focuses on the statistical behavior of the entanglement indicators over two generic state ensembles -- the Hilbert-Schmidt ensemble and the fermionic Gaussian ensemble. For the Hilbert-Schmidt …
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One- and two-photon states for quantum information
… above the Werner-state boundary in the linear entropy-tangle plane. In addition, we demonstrate that such states can be efficiently concentrated via a “Procrustean method,” simultaneously increasing both the purity and the degree of entanglement. Our experimental MEMS creation directed us to …
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Ricci Curvature of Noncommutative Three Tori, Entropy, and Second Quantization
… function $f$. In chapter 3, we show that the von Neumann entropy, average energy, and negative free energy of the Gibbs state of the second quantized Dirac operator $dGamma D$ has a spectral action functional interpretation of the original Dirac operator $D$. To be able to carry on the …
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Multiple-user quantum information theory for optical communication channels
… of a conjecture on the minimum output von Neumann entropy. In the first part of this thesis, we evaluate the optimum capacity for free-space line-of-sight optical communication using Gaussian-attenuation apertures. Optimal power allocation across all the spatiotemporal modes is studied, …
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The life of quanta : entanglement wormholes and the second law
… = EPR conjecture that relates the entanglement entropy of a collection of black holes to the cross sectional area of Einstein-Rosen (ER) bridges (or wormholes) connecting them. We show that the geometrical entropy of classical ER bridges satisfies the subadditivity, triangle, strong …
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Aspects of the reflected entropy
… information quantity, called the reflected entropy, which is a measure of quantum correlations in mixed states. Our work is motivated by, and generalizes, an earlier work on the thermo-field double purification of thermal states, in the purview of the AdS/CFT correspondence. Our main result …
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Quantum Resource Distributions: Geometric Analysis and Computational Classification
… measures such as tangle, concurrence, von Neumann entropy, and negativity. By comparing universal (Clifford+T) and non-universal (Clifford-only) architectures, we show that universal sets enable access to more expressive, statistically rich regions of Hilbert space, while Clifford …
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Classical, quantum and numerical aspects of modified theories of gravity
… such a set-up, we compute the concurrence and von Neumann entropy for the entanglement and show that an increase in the length scale of nonlocality leads to a decrease in both of the aforementioned quantities. Our attention is then turned to two specific two-dimensional dilaton gravity models; …
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Entropic Continuity Bounds & Eventually Entanglement-Breaking Channels
… of the Audenaert-Fannes continuity bound for the von Neumann entropy, and the necessary and sufficient conditions for its saturation, in a universal framework which extends to the other functions, including the Rényi and Tsallis entropies. In particular, we prove a novel uniform continuity bound …
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Scaling of entanglement entropy in some condensed matter systems
… thesis focuses on the scaling of entanglement entropy in lower dimensions and is divided into three main parts. Chapter 2 studies the thermal reduced density matrices in fermion and spin systems on ladders. Chapter 3 studies the many-body localization phase transition in a Rokhsar-Kivelson type …