Nonequilibrium Kondo effect in a magnetic field: Auxiliary master equation approach

We solve the single-impurity Anderson model in a magnetic field and out of equilibrium with an auxiliary master equation approach [1,2,3]. Treating the master equation within the framework of matrix product states allows us to generate highly accurate results, especially for the spectral functions. In equilibrium we find a remarkable agreement to spectral functions achieved with NRG, cf. [3]. The application of a bias voltage V and a magnetic field B both individually result in a splitting of the Kondo resonance around the Kondo temperature. With our method we can resolve a four-peak structure in the spectral function for nonzero B and V, due to both effects. This four-peak structure manifests itself in the differential conductance, which is very well accessible by experiments. We finally compare our results to recent experiments [4,5,6] and draw conclusions about the underlying spectral functions. We find that our results nicely agree with experimental data also outside the Kondo regime.


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[3] A. Dorda et al., Phys. Rev. B 92, 125145 (2015)
[4] A. V. Kretinin et al., Phys. Rev. B 84, 245316 (2011)
[5] A. V. Kretinin et al., Phys. Rev. B 85, 201301(R) (2012)
[6] M. Ferrier et al., Nat. Phys. 12, 230 (2016)