Title

Quantum Phase Transitions in Electronic Systems

Abstract

Quantum phase transitions occur at zero temperature when some non-thermal control-parameter like pressure or chemical composition is changed. They are driven by quantum rather than thermal fluctuations. In this review we first give a pedagogical introduction to quantum phase transitions and quantum critical behavior emphasizing similarities with and differences to classical thermal phase transitions. We then illustrate the general concepts by discussing a few examples of quantum phase transitions occurring in electronic systems. The ferromagnetic transition of itinerant electrons shows a very rich behavior since the magnetization couples to additional electronic soft modes which generates an effective long-range interaction between the spin fluctuations. We then consider the influence of rare regions on quantum phase transitions in systems with quenched disorder, taking the antiferromagnetic transitions of itinerant electrons as a primary example. Finally we discuss some aspects of the metal-insulator transition in the presence of quenched disorder and interactions.

Department(s)

Physics

Keywords and Phrases

Antiferromagnetism; Electron transitions; Ferromagnetism; Magnetic materials; Magnetization; Phase transitions; Itinerant magnets; Metal-insulator transition; Quantum phase transition; Quantum electronics

International Standard Serial Number (ISSN)

0003-3804

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2000 Wiley-VCH Verlag Berlin GmbH, All rights reserved.

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