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Electron‐electron interactions and the metal‐insulator transition in heavily doped silicon
Author(s) -
v. Löhneysen H.
Publication year - 2011
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.201100034
Subject(s) - condensed matter physics , electron , coulomb , metal–insulator transition , doping , materials science , scaling , semiconductor , exponent , conductivity , hubbard model , critical exponent , metal , physics , phase transition , superconductivity , quantum mechanics , linguistics , philosophy , geometry , mathematics , optoelectronics , metallurgy
The metal‐insulator (MI) transition in Si:P can be tuned by varying the P concentration or – for barely insulating samples – by application of uniaxial stress S. On‐site Coulomb interactions lead to the formation of localized magnetic moments and the Kondo effect on the metallic side, and to a Hubbard splitting of the donor band on the insulating side. Continuous stress tuning allows the observation of finite‐temperature dynamic scaling of σ (T,S) and hence a reliable determination of the critical exponent μ of the extrapolated zero‐temperature conductivity σ (0) ∼ | S ‐ S c | μ , i.e., μ = 1, and of the dynamical exponent z = 3. The issue of half‐filling vs. away from half‐filling of the donor band (i.e., uncompensated vs. compensated semiconductors) is discussed in detail.