Quantum Phase Transitions in Two Dimensional Electron Systems Under Strong Magnetic Field PDF Download

Author: Dongzi Liu
Publisher:
ISBN:
Category : Magnetic fields
Languages : en
Pages : 334

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Author: Katherine A. Schreiber
Publisher: Springer Nature
ISBN: 3030263223
Category : Science
Languages : en
Pages : 101

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This thesis presents the discovery of a surprising phase transition between a topological and a broken symmetry phase. Phase transitions between broken symmetry phases involve a change in symmetry and those between topological phases require a change in topological order; in rare cases, however, transitions may occur between these two broad classes of phases in which the vanishing of the topological order is accompanied by the emergence of a broken symmetry. This thesis describes observations of such a special phase transition in the two-dimensional electron gas confined in the GaAs/AlGaAs structures. When tuned by hydrostatic pressure, the ν = 5/2 and ν = 7/2 fractional quantum Hall states, believed to be prototypical non-Abelian topological phases of the Pfaffian universality class, give way to an electronic nematic phase. Remarkably, the fractional quantum Hall states involved are due to pairing of emergent particles called composite fermions. The findings reported here, therefore, provide an interesting example of competition of pairing and nematicity. This thesis provides an introduction to quantum Hall physics of the two-dimensional electron gas, contains details of the high pressure experiments, and offers a discussion of the ramifications and of the origins of the newly reported phase transition.

Author: Babak Hosseinkhani
Publisher:
ISBN:
Category :
Languages : en
Pages : 154

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Author: Subir Sachdev
Publisher: Cambridge University Press
ISBN: 9780521004541
Category : Mathematics
Languages : en
Pages : 374

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Quantum Phase Transitions is the first book to describe in detail the fundamental changes that can occur in the macroscopic nature of matter at zero temperature due to small variations in a given external parameter. The subject plays a central role in the study of the electrical and magnetic properties of numerous important solid state materials. The author begins by developing the theory of quantum phase transitions in the simplest possible class of non-disordered, interacting systems - the quantum Ising and rotor models. Particular attention is paid to their non-zero temperature dynamic and transport properties in the vicinity of the quantum critical point. Several other quantum phase transitions of increasing complexity are then discussed and clarified. Throughout, the author interweaves experimental results with presentation of theoretical models, and well over 500 references are included. The book will be of great interest to graduate students and researchers in condensed matter physics.

Author: Subir Sachdev
Publisher: Cambridge University Press
ISBN: 113950021X
Category : Science
Languages : en
Pages : 521

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Book Description
Describing the physical properties of quantum materials near critical points with long-range many-body quantum entanglement, this book introduces readers to the basic theory of quantum phases, their phase transitions and their observable properties. This second edition begins with a new section suitable for an introductory course on quantum phase transitions, assuming no prior knowledge of quantum field theory. It also contains several new chapters to cover important recent advances, such as the Fermi gas near unitarity, Dirac fermions, Fermi liquids and their phase transitions, quantum magnetism, and solvable models obtained from string theory. After introducing the basic theory, it moves on to a detailed description of the canonical quantum-critical phase diagram at non-zero temperatures. Finally, a variety of more complex models are explored. This book is ideal for graduate students and researchers in condensed matter physics and particle and string theory.

Author: Lincoln Carr
Publisher: CRC Press
ISBN: 1439802610
Category : Science
Languages : en
Pages : 756

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Quantum phase transitions (QPTs) offer wonderful examples of the radical macroscopic effects inherent in quantum physics: phase changes between different forms of matter driven by quantum rather than thermal fluctuations, typically at very low temperatures. QPTs provide new insight into outstanding problems such as high-temperature superconductivit

Author: Xin Wan
Publisher:
ISBN:
Category :
Languages : en
Pages : 282

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Author: Vladimir Dobrosavljevic
Publisher: Oxford University Press
ISBN: 0199592594
Category : Science
Languages : en
Pages : 583

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When many particles come together how do they organize themselves? And what destroys this organization? Combining experiments and theory, this book describes intriguing quantum phases - metals, superconductors and insulators - and transitions between them. It captures the excitement and the controversies on topics at the forefront of research.

Author: Sergey Kravchenko
Publisher: CRC Press
ISBN: 9814745383
Category : Science
Languages : en
Pages : 244

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Book Description
The properties of strongly correlated electrons confined in two dimensions are a forefront area of modern condensed matter physics. In the past two or three decades, strongly correlated electron systems have garnered a great deal of scientific interest due to their unique and often unpredictable behavior. Two of many examples are the metallic state and the metal–insulator transition discovered in 2D semiconductors: phenomena that cannot occur in noninteracting systems. Tremendous efforts have been made, in both theory and experiment, to create an adequate understanding of the situation; however, a consensus has still not been reached. Strongly Correlated Electrons in Two Dimensions compiles and details cutting-edge research in experimental and theoretical physics of strongly correlated electron systems by leading scientists in the field. The book covers recent theoretical work exploring the quantum criticality of Mott and Wigner–Mott transitions, experiments on the metal–insulator transition and related phenomena in clean and dilute systems, the effect of spin and isospin degrees of freedom on low-temperature transport in two dimensions, electron transport near the 2D Mott transition, experimentally observed temperature and magnetic field dependencies of resistivity in silicon-based systems with different levels of disorder, and microscopic theory of the interacting electrons in two dimensions. Edited by Sergey Kravchenko, a prominent experimentalist, this book will appeal to advanced graduate-level students and researchers specializing in condensed matter physics, nanophysics, and low-temperature physics, especially those involved in the science of strong correlations, 2D semiconductors, and conductor–insulator transitions.

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

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Quantum phase transitions are among the most intriguing topics in modern condensed matter physics. Interesting physical phenomena usually emerge in the vicinity of quantum critical points, making the investigation of such quantum systems particularly rewarding. In this thesis we present studies related to quantum phase transitions in two compounds, FBBO and Sr3Ru2O7, using hydrostatic pressure as the tuning parameter. Pressure is an ideal parameter to tune the strength of various interactions within the sample by changing the lattice constants, but is known to be very challenging to apply experimentally. Therefore a major effort of my PhD is to find out a consistent and systematic approach to prepare such experiments. FBBO is a neutral organic radical that has been carefully designed to be as metallic as possible at ambient pressure. Nevertheless it is still insulating, and high pressure was required in order to drive this system through the metal-insulator transition. Here, I present strong evidence of the formation of a Fermi liquid ground state under 6.2 GPa [1]. This is the first such observation for a neutral organic radical, after being proposed for decades. In the approach to metallization, we also found intriguing evidence of a low temperature magnetic phase. The c-axis resistivity of the itinerant metamagnet Sr3Ru2O7 has also been measured under pressure. The initial goal was to search for superconductivity, largely because of the interesting unconventional superconducting ground state found in its close sibling, Sr214. In particular, the c-axis conductivity was measured to rule out possible Sr2RuO4 inclusions within the sample. No superconductivity was found up to the highest pressures of 5.8 GPa and 4.7 GPa respectively in the two independent sets of measurements. Instead, we found that the high temperature resistance falls substantially with increasing pressure, unlike what has been reported for Sr214. The metamagnetic transition shifts rapidly with pressure to higher magnetic field. More importantly, power-law analysis at low temperatures at various pressures indicates that the strength of the electron-electron interaction decays rapidly with increasing pressure. This offers a natural explanation for our failure to induce superconductivity at high pressures.