Lifshitz transition in triangular lattice Kondo-Heisenberg model |
(a) The ground-state energy Eg and (b) the first derivative dEg/dJH versus the Heisenberg interaction JH for NN electron hopping but with NNN hole hopping, where the parameters are t = 1, t1/t = 0.3, nc = 0.9, JK = 2.5. |