Anderson impurity in a semiconductor

Journal Article · Sun Sep 01 04:00:00 EDT 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.54.8556· OSTI ID:383823

Yu, C C; Guerrero, M ^[1]

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1. Department of Physics and Astronomy, University of California, Irvine, California 92697-4575 (United States)

We study an Anderson impurity in a semiconducting host using the density matrix renormalization group technique. We use the {ital U}=0 one-dimensional Anderson Hamiltonian at half filling as the semiconducting host since it has a hybridization gap. By varying the hybridization of the host, we can control the size of the semiconducting gap {Delta}. We consider chains with 25 sites and we place the Anderson impurity (with {ital U}{approx_gt}0) in the middle of the chain. We dope the half-filled system with one hole and we find two regimes: when the hybridization of the impurity is small such that the energy {Delta}{ital E} to add a hole to the impurity site is less than {Delta}/2, the hole density and the spin are localized near the impurity. When the hybridization of the impurity is large ({Delta}{ital E}{approx_gt}{Delta}/2), the hole and spin density are spread over the lattice. Additional holes avoid the impurity and are extended throughout the lattice. Away from half filling, the semiconductor with an impurity is analogous to a double well potential with a very high barrier. We also examine the chemical potential as a function of electron filling, and we find that the impurity introduces midgap states when the impurity hybridization is small. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 383823
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 12 Vol. 54; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANDERSON MODEL
CHEMICAL POTENTIAL
DENSITY MATRIX
ENERGY GAP
HYBRIDIZATION
IMPURITIES
ONE-DIMENSIONAL CALCULATIONS
RENORMALIZATION
SEMICONDUCTOR MATERIALS