  Strange metal behavior arises in heavy fermion metals close to
antiferromagnetic transitions. An increasing amount of experiments indicates a
link of such behavior to a Kondo breakdown quantum critical point. To shed
light on this intriguing problem, we study the 2D Kondo-Heisenberg model using
a dynamical large-N multichannel Schwinger boson approach. We identify and
characterize the quantum phase transition from an antiferromagnetically ordered
ground state to a Kondo-dominated paramagnetic state, and attribute a jump in
certain phase shift to Kondo breakdown. In addition, we calculate transport and
thermodynamic quantities and discuss them in the context of the experimental
observations in quantum critical heavy fermion systems.
