Phase diagram of the SU(2) Kondo lattice

Journal Article · 27 September 2018 · AIP Advances

DOI: https://doi.org/10.1063/1.5043080 · OSTI ID:1609366

Abele, Miguel ^[1]; Riseborough, P. S. ^[2]

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1. Temple Univ., Philadelphia, PA (United States); DOE/OSTI
2. Temple Univ., Philadelphia, PA (United States)

We examine the SU(2) Kondo Lattice Model, for simple cubic lattices with various magnitudes of the localized spins j and numbers of conduction electrons, nc. For j=1/2, the system undergoes transitions from the paramagnetic to magnetically ordered states. The sequence of low-temperature magnetic states found on increasing n_c is symmetric about half-filling and exhibits a preference for commensurate phases over incommensurate phases. On increasing nc from small values, the sequence of magnetic orderings consists of: ferromagnetic phases, planes of ferromagnetically spins which are sequentially twisted by nc-dependent angles, ferromagnetic planes of spins that are aligned antiferromagnetically, antiferromagnetic planes of spins in which the Neel order parameters are twisted through incommensurate angles. Neel order is most stable around half-filling. Magnetic ordered phases are found to be more stable than the Kondo phase for j=1/2, but larger j values may stabilize the Kondo phase. For j=3/2 the sequence of magnetic ordering with increasing nc is the same but, depending on the value of the strength of the Kondo interaction, the Kondo phase may be stabilized in a window 4 ≥ n_c ≥ 2. In accordance with Nozieres’s arguments, we find that magnetic ordering is dominant for almost filled and almost empty bands.

• Research Organization: Temple Univ., Philadelphia, PA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: FG02-01ER45872
• OSTI ID: 1609366
• Journal Information: AIP Advances, Journal Name: AIP Advances Journal Issue: 10 Vol. 8; ISSN 2158-3226
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English