# Quantum phase transition in a two-dimensional Kondo-Heisenberg model: a Schwinger-boson large-N approach

## TL;DR

This paper investigates the quantum phase transition in a 2D Kondo-Heisenberg model using a large-N Schwinger boson approach, revealing insights into Kondo breakdown and strange metal behavior near quantum critical points.

## Contribution

It introduces a dynamical large-N multichannel Schwinger boson method to analyze the quantum phase transition and Kondo breakdown in the 2D Kondo-Heisenberg model, linking theory to experimental phenomena.

## Key findings

- Identification of a quantum phase transition from antiferromagnetic to Kondo-dominated states
- Observation of a phase shift jump indicating Kondo breakdown
- Calculation of transport and thermodynamic properties consistent with experiments

## Abstract

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.