Antiferromagnetism and Stripe Channel Order in the SU (N) -Symmetric Two-Channel Kondo Lattice Model

We carry out large-scale, sign-problem-free determinant quantum Monte Carlo simulations of the square lattice SU(N)-symmetric two-channel Kondo lattice model at half-filling. We map out the zero-temperature phase diagram for N=2, 4, 6, and 8, as a function of the Kondo coupling strength. In the weak-coupling regime, we observe antiferromagnetic order of the localized moments. Remarkably, for N≥6, sufficiently strong Kondo coupling induces spontaneous channel symmetry breaking, forming a stripe dimerization pattern with a wave vector k=(π,0) alternating between channels. These findings are supported by a complementary large-N saddle point analysis, which identifies the striped hybridization pattern as the energetically preferred configuration. The spatial symmetry breaking results in an anisotropic Fermi surface reconstruction.