Quantum Criticality of Kondo Lattice Model: A Renormalization Group Study via Quantum non-Linear Sigma Model*

Quantum criticality has attracted considerable interest in many strongly correlated systems. Heavy fermion metals represent a prototype of such systems [1]. Here the interplay between local moments and itinerant electrons introduces novel quantum phase transitions and critical properties, but also presents a challenge to theoretical understanding. In this work, we approach the problem from the magnetically ordered side and analyze Kondo lattice models in a quantum nonlinear sigma model representation. By treating the local moments and itinerant electrons on an equal footing, we analyze the competition between the Kondo and RKKY couplings using a renormalization group analysis. Our results shed new light on the global phase diagram of the heavy fermion systems [2] and, especially, the behavior of the frustrated Kondo lattice systems [3,4].

[1] S. Paschen & Q. Si, Nat. Rev. Phys. 3, 9 (2021); S. Kirchner et al, Rev. Mod. Phys. 92, 011002 (2020); Q. Si et al., Nature 413, 804 (2001).
[2] Q. Si, Physica B378, 23 (2006); Phys. Status Solidi B 247, 476 (2010).
[3] H. Zhao et al, Nat. Phys. 15, 1261 (2019).
[4] M. Kavai et al, Nat. Commun. 12, 1377 (2021).
*NSF Grant # DMR-1920740 & Welch Foundation Grant # C-1411.