Dresden 2014 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 50: Correlated Electrons: Quantum-Critical Phenomena - Theory
TT 50.8: Vortrag
Dienstag, 1. April 2014, 15:45–16:00, BEY 81
Anderson Metal-Insulator Transitions With Classical Magnetic Impurities — •Daniel Jung1, Keith Slevin2, and Stefan Kettemann1,3 — 1School of Engineering and Science, Jacobs University Bremen, 28759 Bremen, Germany. — 2Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan. — 3Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea.
We study the effects of classical magnetic impurities on the Anderson
metal-insulator transition numerically [1, 2]. In particular we find that while
a finite concentration of Ising impurities lowers the critical value of the
site-diagonal disorder amplitude Wc, in the presence of Heisenberg
impurities, Wc is first enhanced with increasing exchange coupling
strength J due to time-reversal symmetry breaking. The resulting scaling with
J is analyzed and compared to analytical predictions by Wegner [3]. We
discuss the relevance of our findings for systems like phosphor-doped silicon,
which are known to exhibit a quantum phase transition from metal to insulator
driven by the interplay of both interaction and disorder, accompanied by the
presence of a finite concentration of magnetic moments [4].
D. Jung, and S. Kettemann, AIP conf. proceed., submitted.
D. Jung, K. Slevin, and S. Kettemann, to be published.
F. Wegner, Nucl. Phys. B 280, 210 (1987).
H. von Löhneysen, Adv. Solid State Phys. 40, 143 (2000)