Physical properties of a new coherent state of the almost-degenerate infinite-U lattice Anderson model

Journal Article · Wed Apr 01 00:00:00 EST 1992 · Journal of Low Temperature Physics; (United States)

DOI:https://doi.org/10.1007/BF00141564· OSTI ID:5167914

Tolpin, A E ^[1]

---

1. Naval Research Lab., Washington, DC (United States)

A new approach toward understanding the heavy-fermion systems (HFS) within a framework of the almost-degenerate lattice Anderson Hamiltonian in the Kondo regime is proposed. In the coherent low-temperature regime, operators in the effective Hamiltonian are found to belong to an SU(2J + 3) dynamical algebra. A canonical transformation is employed to decouple the quasiparticle branches, thereby setting up the decoupling equation. It is found that this decoupling equation has a solution of the symmetry-altering type. The thermodynamic response functions and other quantities are calculated for this new state. This solution is a consequence of the degeneracy of the uncoupled f-orbitals. It is characterized by the interatomic hopping of f-electrons, which produces the spin-delocalization regime and with the renormalized f-level pinned close to the Fermi level. This is also found to be the source of the apparent spin-compensation regime, which is accompanied by large enhancement of the thermodynamic response functions. In addition, the calculated phase coherence length is found to be much greater than a lattice constant, thereby showing a many-body character of this new state. It is believed that this new state provides an accurate description of the heavy-fermion state at low temperatures. The stability conditions for the new regime are also discussed.

• OSTI ID: 5167914
• Journal Information: Journal of Low Temperature Physics; (United States), Vol. 87:1-2; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
FERMI STATISTICS
CANONICAL TRANSFORMATIONS
DECOUPLING
FERMIONS
HAMILTONIANS
KONDO EFFECT
LATTICE FIELD THEORY
PROPAGATOR
QUASI PARTICLES
SU-2 GROUPS
FIELD THEORIES
LIE GROUPS
MATHEMATICAL OPERATORS
QUANTUM FIELD THEORY
QUANTUM OPERATORS
SU GROUPS
SYMMETRY GROUPS
TRANSFORMATIONS
665400* - Quantum Physics Aspects of Condensed Matter- (1992-)