Global phase diagram of the Ising-anisotropic Kondo lattice

In recent years, a significant amount of work has been dedicated to understanding heavy-fermion quantum criticality. What has emerged is a proposed global phase diagram [1] meant to capture the interplay between Kondo singlet formation, magnetic ordering and intrinsic fluctuations associated with the quantum-mechanical nature of the local moments. Using an Extended Dynamical Mean-Field Theory (EDMFT) approach, we study a prototypical Ising-anisotropic Kondo lattice model in the presence of a transverse field that provides a way of controlling the quantum fluctuations of the local moments. We show that the transverse field opens up a line of continuous transitions directly from an antiferromagnetic phase with Kondo destruction (and, hence, a small Fermi surface) to a paramagnetic heavy-fermion state (with a large Fermi surface). We show that the critical scaling characteristics along this line are the same as for the previously studied zero-transverse field case, indicating the robustness of the Kondo-destruction scenario with respect to enhanced quantum fluctuations. General implications of our results for the global phase diagram and heavy-fermion quantum criticality will be discussed. [1] ``Kondo Destruction and Quantum Criticality in Kondo Lattice Systems,'' Q. Si, J. H. Pixley, E. Nica, S. J. Yamamoto, P. Goswami, R. Yu, and S. Kirchner, J. Phys. Soc. Jpn. \textbf{83, }061005 (2014).