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 20 of 37 for “"Entanglement entropy"”.
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Entanglement entropy in integrable quantum systems
… In all but one publications, we compute the entanglement of various systems. Using the celebrated “replica trick” we compute the entanglement entropy of non unitary systems using integrable tools in continuum and discrete models. In particular, in the first article we generalise the method …
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Scaling of entanglement entropy in some condensed matter systems
The following 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 …
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Entanglement entropy, the Ryu-Takayanagi prescription, and conformal maps
… underpinning the Ryu-Takayanagi prescription for entanglement entropy in a holographic theory. We begin by constructing entanglement entropy in finite-dimensional quantum systems, and defining the boundary at infinity of a bulk spacetime. This is sufficient for a naïve application of the …
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Universal properties of the entanglement entropy in quantum integrable models
… et al. [2008] with the purpose of quantifying entanglement in a quantum field theory, and have a deeper understanding of their predicting power on lattice systems. The first chapter is meant to be a review of quantum entanglement in many-body physics, and the methods we use to establish the …
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Counting degrees of freedom in quantum field theory using entanglement entropy
… fixed point. We argue that a refinement of entanglement entropy is a promising candidate for such measure. Indeed, in two and three spacetime dimensions the number of degrees of freedom defined this way can be proven to monotonically decrease under RG flows. Firstly, we define renormalized …
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Conformal Field Theory Descriptions of String Initial Conditions and Quantum Entanglement Entropy
… is most bizarre from a classical perspective is entanglement. This effect is the driving force behind the growing interest in quantum information. From entanglement, one is naturally led to the concept of entanglement entropy as a measure of the maximal amount of information which can be stored …
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Studies on two topics in theoretical physics: Entanglement entropy and holographic superconductors
… consists of the _rst two chapters, studying the entanglement entropy. The second part consists of the third chapter, dealing with holographic superconductors. In chapter one we calculate the topological entanglement entropy of Chern-Simons theories in 2+1 dimensions. We employ a procedure of …
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The scaling behavior of the entanglement entropy in 2+1 dimensional critical systems
The entanglement entropy in 1+1 dimensional critical system has been well studied and known to have a universal scaling form that gives information about the underlying critical system. While the case for 1+1 dimensional critical systems has been well studied, the situation in higher dimensional …
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Studies in: entanglement entropy of two dimensional quasi-topological quantum field theory and geometry of the exact renormalization group and higher spin holography
Part I: Entanglement Entropy of 2d Quasi-Topological Quantum Field Theory We compute the entanglement entropy of two-dimensional quasi-topological quantum field the- ories (QTFTs). These are theories in which the correlation functions depend on the topology and on the total area of the underlying …
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The life of quanta : entanglement wormholes and the second law
… of the ER = 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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Gauge/Gravity Duality: Recovering the Bulk from the Boundary using AdS/CFT
… in the bulk spacetime) and the holographic entanglement entropy proposal (relating the entanglement entropy of certain subsystems on the boundary to the area of static minimal surfaces) to recover the bulk metric. Using null and zero-energy spacelike boundary-to-boundary geodesic probes, we …
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Aspects of amplitudes, gravity & complexity
… amplitudes in gravitational theories and entanglement entropy & complexity in quantum field theory. In part one, we utilise modern scattering amplitude techniques to efficiently calculate the deflection angle of both light and gravity due to the presence of a massive body. We find this to …
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Aspects of quantum entanglement in critical and topologically ordered systems
Quantum entanglement plays an important role in characterizing the property of many-body systems and quantum field theories. In this thesis, we study the quantum entanglement in (1+1)-dimensional critical systems and (2+1)-dimensional topologically ordered phases. For (1+1)-d critical systems, we …
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Inflationary cosmology and fundamental physics
… second half, we examine other topics: oscillons, entanglement entropy, and the Casimir effect. In particular, we compute the quantum decay of oscillons, finding it to be dramatically different to the classical decay; we establish finite contributions to the entanglement entropy between a pair of …
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Chaos and Thermalization in Quantum Many-Body Systems and Gravity
… us to calculate correlation measures such as entanglement entropy or logarithmic negativity, as well as measures of information recovery from subsystems, in chaotic systems ranging from spin chains and quantum field theories to black holes. For evaporating black holes, the equilibrium …
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Studies of Integrable One-Dimensional Quantum Systems
… I introduce the spatial von Neumann bipartite entanglement entropy and use the BA in order to calculate this entropy in the Lieb–Liniger model.
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Entanglement, topology, & renormalization
In this thesis we will explore entanglement of various subsystems in quantum field theory, and its uses for describing underlying structure of states. We begin this journey by focusing on topological quantum field theory in chapters 1 and 2. These chapters are based heavily upon the papers [1] and …
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New perspectives on fractional quantum Hall physics
… field theory dualities, and (3) the use of entanglement entropy in characterizing interfaces of FQH states. In the first part, we examine phases of matter known as fractional Chern insulators (FCIs), lattice analogues of FQH states. We begin in Chapter 2 by formulating a composite fermion …
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Entanglement in gauge/ gravity duality
… studies that elucidate the relationship between entanglement in strongly coupled gauge theories and the geometry of their gravity duals. In the first, we find that in a certain class of time-dependent states which have a gravity dual in which a black hole forms, the entanglement entropy of large …
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Many-body localization and tensor networks
… gates. Chapter 5 studies the distribution of the entanglement entropy in the MBL-ergodic transition region. Chapter 6 studies the the influence of pseudo-spin SU (2) symmetry on the MBL phase. Chapter 7 is a side project that studies the influence of the duality-twisted boundary conditions on the …
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