The magnitude of the magnetic exchange interaction in the heavy fermion   antiferromagnet CeRhIn$_5$
  We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy fermion antiferromagnet CeRhIn$_5$. The spin wave dispersion can be quantitatively reproduced with a simple $J_1$-$J_2$ model that also naturally explains the magnetic spin-spiral ground state of CeRhIn$_5$ and yields a dominant in-plane nearest-neighbor magnetic exchange constant $J_0$ = 0.74 meV. Our results pave the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent Ce$T$In$_5$ ($T$ = Co, Rh, Ir) class of heavy fermion materials. 
Pinaki Das (1), S.-Z. Lin (2), N. J. Ghimire (1), K. Huang (1 and 3),   F. Ronning (1), E. D. Bauer (1), J. D. Thompson (1),...
cond-mat.str-el