RKKY Interactions and Multipole Order in Ab initio Wannier Model of CeCoSi

Abstract

We calculate the RKKY interactions derived from ab initio calculations for the intermetallic compound CeCoSi exhibiting the hidden nonmagnetic order at $T_0$ and examine the instability towards possible multipole orders within the random phase approximation. All 36 multipole interactions up to rank 5 are investigated, and the maximum susceptibility exhibits an antiferro order with $\mathbf{q}=0$ for nonmagnetic multipoles of monopole $I$ and hexadecapole $H_0$, yielding a charge imbalance of $f$ electrons at two Ce atoms in the unit cell. The obtained order can explain some experiments.

5 pages, 5 figures with supplemental material (11 pages, 2 figures), accepted for publication in JPSJ

References in corpus (6)

• Emergent Rank-5 'Nematic' Order in URu2Si2
• Odd-Parity Multipoles by Staggered Magnetic Dipole and Electric Quadrupole Orderings in CeCoSi
• NQR and NMR spectra in odd-parity multipole material CeCoSi
• Structural Transition in the Hidden Ordered Phase of CeCoSi
• Unusual Nonmagnetic Ordered State in CeCoSi Revealed by ${}^{59}$Co-NMR and NQR Measurements
• Ferroic quadrupolar ordering in CeCoSi revealed using ${}^{59}$Co-NMR measurements