Strongly Correlated Systems: Transport, Entanglement, and Dynamics PDF Download

Author: Younes Javanmard
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description

Author: Joseph C. Szabo
Publisher:
ISBN:
Category : Condensed matter
Languages : en
Pages : 0

View

Book Description
Understanding and identifying quantum phases have been longstanding pursuits in the field condensed matter physics. The most exciting modern problems lie at the intersection of strong correlations and quantum information where highly entangled phases of matter are the most difficult to solve both analytically and computationally. The overarching aim of this thesis is to advance our understanding of strongly correlated materials in light of advanced, microscopic measurement techniques, capable of imaging and manipulating single qubits and measuring fascinating physics such as quantum entanglement. We begin our study with the Fermi-Hubbard model, a theoretical model that captures the insulating and conducting phases of high-temperature superconducting materials, and we end our discussion by characterizing novel quantum phases and dynamics realized on cutting-edge quantum simulation platforms. Our first focus is on the repulsive Fermi-Hubbard model. We elucidate the mechanism by which a Mott insulator transforms into a non-Fermi liquid metal upon increasing disorder at half filling. By correlating maps of the local density of states, the local magnetization, and the local bond conductivity, we find a collapse of the Mott gap toward a V-shape pseudogapped density of states that occurs concomitantly with the decrease of magnetism around the highly disordered sites, while the electronic bond conductivity increases. We propose that these metallic regions percolate to form an emergent non-Fermi liquid phase with a conductivity that increases with temperature. Our results provide one of the first microscopic investigations of dynamical response and how these two phases (correlated metal and Mott insulator) coexist microscopically and lead to an overall macroscopic phase transition. Our work provides novel predictions for electron conductivity measured via local microwave impedance combined with charge and spin local spectroscopies. Expanding beyond the ground state properties of interacting matter, revolutionary quantum simulation experiments provide access to new regimes of quantum matter such as dynamical transitions and steady states in nonequilibrium conditions. This allows us to explore the most mind-boggling properties of interacting quantum systems: entanglement. In our first venture exploring the field of nonequilibrium quantum dynamics, we bridge foundational atomic, molecular, and optical (AMO) and condensed matter models. We investigate competing entanglement dynamics in an Ising-spin chain coupled to an external central ancilla qudit. In studying the real-time behavior following a quench from an unentangled spin-ancilla state, we find that the ancilla entanglement entropy tracks the dynamical phase transition in the underlying spin system. In this composite setting, purely spin-spin entanglement metrics such as mutual information and quantum Fisher information (QFI) decay as the ancilla entanglement entropy grows. We define multipartite entanglement loss (MEL) as the difference between collective magnetic fluctuations and QFI, which is zero in the pure spin chain limit. MEL directly quantifies the ancilla's effect on the development of spin-spin entanglement. One of our central results is that we find MEL is proportional to the exponential of entanglement entropy in real-time. Our results provide a platform for exploring composite system entanglement dynamics and suggest that MEL serves as a quantitative estimate of information entropy shared between collective spins and the ancilla qudit. Our results present a new framework that connects physical spin-fluctuations, QFI, and bipartite entanglement entropy between collective quantum systems. We reduce the qudit/bosonic environment to a single (central) qubit as to investigate the scrambling capacity added by a simple c-qubit. We present the novel ring-star Ising model as a bridge between fast-slow scrambling: a locally interacting spin-1/2 system uniformly coupled to a central qubit vertex. Each spin becomes next-nearest neighbor to all others through the c-qubit, where stronger central coupling continuously degrades any sense of locality and achieves effective all-to-all interactions. Meanwhile, the central qubit adds two level structure to all previous eigenstates in the spectrum. We study operator and entanglement dynamics in a nonintegrable ring-star, spin-1/2 Ising model with tunable central spin coupling. As the interaction with the c-spin increases across all sites, we find a surprising transition from super-ballistic scrambling and information growth to continuously restricted sub-ballistic entanglement and increasingly inhibited operator growth. This slow growth occurs on intermediate timescales that extend exponentially with increasing coupling, indicative of logarithmic entanglement growth. We provide exact dynamics of small systems working with non-equilibrium, effective infinite temperature states, and additionally contribute analytic early-time expansions that support the observed rapid scrambling to quantum Zeno-like crossover. Finally, we apply the properties of entanglement to highlight numerically approximate methods for simulating quantum and semiclassical systems. When entanglement slowly develops locally, tensor network methods allow for efficient simulation of the minimal Hilbert space required to store the quantum wavefunction evolving under Schrodinger dynamics or quantum operators under Heisenberg evolution. In the limit of long-range interactions, the system is increasingly semiclassical where the wavefunction spreads rapidly, but the full quantum Hilbert space approaches proximate conservation of collective observables. Here we review tensor network and semiclassical numerical algorithms and provide a brief discussion on applying them to simulate the quench dynamics of the Heisenberg model. We highlight the regimes where we expect them to be accurate and the intermediate regions where the two become approximate from different limits on the range of interaction.

Author: J M P Carmelo
Publisher: World Scientific
ISBN: 9814475831
Category : Technology & Engineering
Languages : en
Pages : 612

View

Book Description
This volume presents a collection of review papers on recent work in the connected areas of strongly correlated systems, the effects of coherence on macroscopic systems, and entanglement in quantum systems. These areas have attracted considerable interest due to their complexity and associated unexpected nontrivial phenomena, and also due to their potential applications in various fields, from materials science to information technology. The coverage includes strongly correlated electronic systems such as low-dimensional complex materials, ordered and disordered spin systems, and aspects of the physics of manganites and graphene, both in equilibrium and far from equilibrium.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Rapid progress in nanotechnology and naofabrication techniques has ushered in a new era of quantum transport experiments. This has in turn heightened the interest in theoretical understanding of nonequilibrium dynamics of strongly correlated quantum systems. This project has advanced the frontiers of understanding in this area along several fronts. For example, we showed that under certain conditions, quantum impurities out of equilibrium can be reformulated in terms of an effective equilibrium theory; this makes it possible to use the gamut of tools available for quantum systems in equilibrium. On a different front, we demonstrated that the elastic power of a transmitted microwave photon in circuit QED systems can exhibit a many-body Kondo resonance. We also showed that under many circumstances, bipartite fluctuations of particle number provide an effective tool for studying many-body physics--particularly the entanglement properties of a many-body system. This implies that it should be possible to measure many-body entanglement in relatively simple and tractable quantum systems. In addition, we studied charge relaxation in quantum RC circuits with a large number of conducting channels, and elucidated its relation to Kondo models in various regimes. We also extended our earlier work on the dynamics of driven and dissipative quantum spin-boson impurity systems, deriving a new formalism that makes it possible to compute the full spin density matrix and spin-spin correlation functions beyond the weak coupling limit. Finally, we provided a comprehensive analysis of the nonequilibrium transport near a quantum phase transition in the case of a spinless dissipative resonant-level model. This project supported the research of two Ph. D. students and two postdoctoral researchers, whose training will allow them to further advance the field in coming years.

Author: Feodor V. Kusmartsev
Publisher: World Scientific
ISBN: 9814289159
Category : Science
Languages : en
Pages : 645

View

Book Description
Pt. A. Statistical mechanics, magnetism, quantum and nonlinear dynamics. The groundstates and phases of the two-dimensional fully frustrated XY model / P. Minnhagen, S. Bernhardsson and B.J. Kim. 2D Ising model with competing interactions and its application to clusters and arrays of [symbol]-rings, graphene and adiabatic quantum computing / A. O'Hare, F.V. Kusmartsev and K.I. Kugel. Concerning the equation of state for a partially ionized system / G.A. Baker Jr. Quasiclassical Fourier path integral quantum correction terms to the kinetic energy of interacting quantum many-body systems / K.A. Gernoth. Ergodicity and chaos in a system of harmonic oscillators / M.H. Lee. Chaotic modes in scale free opinion networks / F.V. Kusmartsev and K.E. Kürten. Astroid curves for a synthetic antiferromagnetic stack in an applied magnetic field / D.M. Forrester [und weitere]. Entanglement properties of quantum many-body wave functions / J.W. Clark [und weitere] -- pt. B. Fermi and Bose fluids. Topological phase transitions in strongly correlated Fermi systems / J.W. Clark, V.A. Khodel and M.V. Zverev. Deconfinement and quantum liquid crystalline states of dipolar fermions in optical lattices / S.T. Carr, J. Quintanilla and J.J. Betouras. On the "generalized Slater" approximation / J. Messud [und weitere]. Fluid helium-4 in thermal equilibrium / K.A. Gernoth and M.L. Ristig. Microscopic approach in the description of slowing of electromagnetic pulses in BEC of alkalis / Y. Slyusarenko and A. Sotnikov. Anomalous behavior of ideal Fermi gas below 2D : The "ideal quantum dot" and the Paul exclusion principle / M. Grether, M. de Llano and M.H. Lee -- pt. C. Transport theory. On the quantum Hall effect in graphene / S. Fujita [und weitere]. Modelling charge transport in DNA using transfer matrices with diagonal terms / S.A. Wells, C.-T. Shih and R.A. Römer. Similarities between embolic stroke and percolation problems / J.P. Hague. Extraordinary magnetoresistance in hybrid semiconductor-metal systems / T.H. Hewett and F.V. Kusmartsev. Topological aspects of the specific heat / C.M. Sarris and A.N. Proto. Effects of electron-electron interactions in two dimensions / S.V. Kravchenko

Author: David Sánchez
Publisher: MDPI
ISBN: 3039433660
Category : Mathematics
Languages : en
Pages : 426

View

Book Description
Mesoscopic physics deals with systems larger than single atoms but small enough to retain their quantum properties. The possibility to create and manipulate conductors of the nanometer scale has given birth to a set of phenomena that have revolutionized physics: quantum Hall effects, persistent currents, weak localization, Coulomb blockade, etc. This Special Issue tackles the latest developments in the field. Contributors discuss time-dependent transport, quantum pumping, nanoscale heat engines and motors, molecular junctions, electron–electron correlations in confined systems, quantum thermo-electrics and current fluctuations. The works included herein represent an up-to-date account of exciting research with a broad impact in both fundamental and applied topics.

Author: Adolfo Avella
Publisher: Springer Science & Business Media
ISBN: 3642351069
Category : Science
Languages : en
Pages : 350

View

Book Description
This volume presents, for the very first time, an exhaustive collection of those modern numerical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and material science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciate consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as possible way, with the working details of a specific technique.

Author: Jingxian Lin
Publisher:
ISBN:
Category : Condensed matter
Languages : en
Pages : 156

View

Book Description

Author: Yuto Ashida
Publisher: Springer Nature
ISBN: 9811525803
Category : Science
Languages : en
Pages : 228

View

Book Description
This book studies the fundamental aspects of many-body physics in quantum systems open to an external world. Recent remarkable developments in the observation and manipulation of quantum matter at the single-quantum level point to a new research area of open many-body systems, where interactions with an external observer and the environment play a major role. The first part of the book elucidates the influence of measurement backaction from an external observer, revealing new types of quantum critical phenomena and out-of-equilibrium dynamics beyond the conventional paradigm of closed systems. In turn, the second part develops a powerful theoretical approach to study the in- and out-of-equilibrium physics of an open quantum system strongly correlated with an external environment, where the entanglement between the system and the environment plays an essential role. The results obtained here offer essential theoretical results for understanding the many-body physics of quantum systems open to an external world, and can be applied to experimental systems in atomic, molecular and optical physics, quantum information science and condensed matter physics.

Author: Bei-Lok B. Hu
Publisher: Cambridge University Press
ISBN: 0521193575
Category : Science
Languages : en
Pages : 615

View

Book Description
An overview of semi-classical gravity theory and stochastic gravity as theories of quantum gravity in curved space-time.