Ground State Properties of Anderson Impurity in a Gapless Host

Abstract

Using the Bethe ansatz method, we study the ground state properties of a $U\to \infty$ Anderson impurity in a ``gapless'' host, where a density of band states vanishes at the Fermi level ${\epsilon }_F$ as $|\epsilon -{\epsilon }_F|$. As in metals, the impurity spin is proven to be screened at arbitrary parameters of the system. However, the impurity occupancy as a function of the bare impurity energy is shown to acquire novel qualitative features which demonstrate a nonuniversal behavior of the system. The latter explains why the Kondo screening is absent (or exists only at quite a large electron-impurity coupling) in earlier studies based on scaling arguments.

5 pages, no figure, RevTex

References in corpus (6)

• Renormalization-group study of Anderson and Kondo impurities in gapless Fermi systems
• Anderson impurity in pseudo-gap Fermi systems
• Overscreening of magnetic impurities in $d_{x^2-y^2}$ wave superconductors
• Exactly Solvable Model of Superconducting Magnetic Alloys
• Bethe ansatz approach to thermodynamics of superconducting magnetic alloys
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Cited by in corpus (2)

• Kondo screening in gapless magnetic alloys
• Hidden Integrability of a Kondo Impurity in an Unconventional Host