Quantum Impurity Far from Equilibrium: Quantum Transport Through a Dissipative Resonant Level Using DMRG*

Using time-dependent matrix product state techniques, we study the quantum transport properties of a dissipative resonant level model, in which a quantum impurity is coupled to two leads and a bosonic bath. Experimentally, this model can be realized by coupling a quantum dot with resistive leads [1]. We focus on the far-from-equilibrium steady states. The non-linear I-V curves and their scaling behavior are presented for different dissipation strengths in the case of both symmetric and asymmetric coupling. In the symmetric setup, a quantum critical point of the two-channel Kondo class is present [2]. To probe properties of the quasiparticle excitations, which can be measured with tunneling spectroscopy, we study the spectral function and shot noise.

[1] HT Mebrahtu, et al., Quantum phase transition in a resonant level coupled to interacting leads, Nature (2012);
[2] HT Mebrahtu, et al., Observation of Majorana quantum critical behaviour in a resonant level coupled to a dissipative environment, Nat. Phys. (2013).