Effect of interactions on density of states and magnetization oscillations in Kondo insulators

We study the effect of interactions on density of states (SdH) and magnetization (dHvA) quantum oscillations (QOs) in Kondo insulators. We consider a hybridization gap insulator and incorporate interactions among the heavy f-electrons using a periodic Anderson model with a Sachdev-Ye-Kitaev (SYK)-like interactions at each site. This model is exactly solvable in the large-N limit. We compute transport to ensure that the system remains insulating at small temperatures. We find that the QO frequencies are not renormalized by interactions: the dHvA oscillations occur at the unhybridized frequency F₀ while the SdH oscillations persist at F₀ ± δF, corresponding to the conduction and valence band edges, just as in the non-interacting system [1]. The QO amplitudes show a remarkable difference: the dHvA amplitude is essentially unaffected by interaction, while the SdH amplitude is strongly enhanced. We will present an analytical understanding of our numerical results.

[1]: A. Panda, S. Banerjee, M. Randeria; Proc. Nat. Acad. Sci. 119, e2208373119 (2022).