- AutorIn
- Younes Javanmard Max Planck Institute for Physics of Complex Systems
- Titel
- Strongly Correlated Systems, Transport, Entanglement, and Dynamics
- Zitierfähige Url:
- https://nbn-resolving.org/urn:nbn:de:bsz:14-qucosa2-331885
- Datum der Einreichung
- 30.08.2018
- Datum der Verteidigung
- 19.12.2018
- Abstract (EN)
- Strongly correlated systems, i.e., quantum materials for which the interactions between its constituents are strong, are good candidates for the development of applications based on quantum-mechanical principles, such as quantum computers. Two paradigmatic models of strongly correlated systems are heavy-fermionic systems and one-dimensional spin-12 systems, with and without quenched disorder. In the past decade, improvement in computational methods and a vast enhancement in computational power has made it possible to study these systems in a a non-perturbative manner. In this thesis we present state-of-the-art numerical methods to investigate the properties of strongly correlated systems, and we apply these methods to solve a couple of selected problems in quantum condensed matter theory. We start by revisiting the phase diagram of the Falicov-Kimball model on the square lattice which can be considered as a heavy-fermionic systems. This model describes an interplay between conduction electrons and heavy electrons and reveals several distinct metal-insulator phase transitions. Using a lattice Monte-Carlo method, we study the transport properties of the model. Our analysis describes the role of temperature and interaction strength on the metal-insulator phase transitions in the Falicov-Kimball model. The second part of the thesis investigate the spatial structure of the entanglement in ground and thermal statesof the transverse-field Ising chain. We use the logarithmic negativity as a measure for the entanglement between two disjoint blocks. We investigate how logarithmic negativity depends on the spatial separation between two blocks, which can be viewed as the entanglement analog of a spatial correlation function. We find sharp entanglement thresholds at a critical distance beyond which the logarithmic negativity vanishes exactly and thus the two blocks become unentangled. Our results hold even in the presence of long-ranged quantum correlations, i.e., at the system’s quantum critical point. Using Time-Evolving Block Decimation (TEBD), we explore this feature as a function of temperature and size of the two blocks. We present a simple model to describe our numerical observations. In the last part of this thesis, we introduce an order parameter for a many-body localized spin-glass (MBL-SG) phase. We show that many-body localized spin-glass order can also be detected from two-site reduced density matrices, which we use to construct an eigenstate spin-glass order parameter. We find that this eigenstate spin-glass order parameter captures spin-glass phases in random Ising chains, both in many-body eigenstates as well as in the nonequilibrium dynamics, from a local in time measurement. We discuss how our results can be used to observe MBL-SG order within current experiments in Rydberg atoms and trapped ion systems.
- Verweis
- Interaction-Tuned Anderson versus Mott Localization
Phys. Rev. Lett. 117, 146601 – Published 28 September 2016
Link: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.146601
DOI: 10.1103/PhysRevLett.117.146601 - Sharp entanglement thresholds in the logarithmic negativity of disjoint blocks in the transverse-field Ising chain
Younes Javanmard et al 2018 New J. Phys. 20 083032
Link: http://iopscience.iop.org/article/10.1088/1367-2630/aad9ba/meta
DOI: 10.1088/1367-2630/aad9ba - Accessing eigenstate spin-glass order from reduced density matrices
Link: https://arxiv.org/abs/1806.02571 - Freie Schlagwörter (EN)
- Strongly Correlated Systems: Transport, Entanglement, and Dynamics
- Klassifikation (DDC)
- 530
- Klassifikation (RVK)
- UP 3600
- GutachterIn
- Prof. Roderich Moessner
- Prof. Jens H Bardarson
- Dr. Markus Heyl
- Prof. Roland Ketzmerick
- BetreuerIn Hochschule / Universität
- Prof. Roderich Moessner
- BetreuerIn - externe Einrichtung
- Prof. Jens H Bardarson
- Den akademischen Grad verleihende / prüfende Institution
- Technische Universität Dresden, Dresden
- URN Qucosa
- urn:nbn:de:bsz:14-qucosa2-331885
- Veröffentlichungsdatum Qucosa
- 15.02.2019
- Dokumenttyp
- Dissertation
- Sprache des Dokumentes
- Englisch
- Lizenz / Rechtehinweis