Transport Signatures of Majorana Quantum Criticality Realized by Dissipative Resonant Tunneling

Abstract

We consider theoretically the transport properties of a spinless resonant electronic level coupled to strongly dissipative leads, in the regime of circuit impedance near the resistance quantum. Using the Luttinger liquid analogy, one obtains an effective Hamiltonian expressed in terms of interacting Majorana fermions, in which all environmental degrees of freedom (leads and electromagnetic modes) are encapsulated in a single fermionic bath. General transport equations for this system are then derived in terms of the Majorana T-matrix. Perturbative treatment of the Majorana interaction term yields the appearance of a marginal, linear dependence of the conductance on temperature when the system is tuned to its quantum critical point, in agreement with recent experimental observations. We investigate in detail the different crossovers involved in the problem, and analyze the role of the interaction terms in the transport scaling functions. In particular, we show that single barrier scaling applies when the system is slightly tuned away from its Majorana critical point, strengthening the general picture of dynamical Coulomb blockade.

10 pages, 4 figures

References in corpus (7)

• Observation of the two-channel Kondo effect
• Quantum Phase Transition in a Resonant Level Coupled to Interacting Leads
• Kondo physics and dissipation: A numerical renormalization-group approach to Bose-Fermi Kondo models
• Dissipation-induced quantum phase transition in a quantum box
• Resonant Tunneling in a Dissipative Environment
• Transport of interacting electrons through a potential barrier: nonperturbative RG approach
• Quantum phase transitions in a resonant-level model with dissipation: Renormalization-group studies

Cited by in corpus (4)

• Does delta-$T$ noise probe quantum statistics?
• Universal conductance scaling of Andreev reflections using a dissipative probe
• Conductance of a Dissipative Quantum Dot: Nonequilibrium Crossover Near a Non-Fermi-Liquid Quantum Critical Point
• Influence of topological degeneracy on the boundary Berezinskii-Kosterlitz-Thouless quantum phase transition of a dissipative resonant level