Abstract
We investigate a well-studied system of a quantum dot coupled to a Coulomb box and leads, realizing a spin-flavor Kondo model. It exhibits a recently discovered non-Fermi liquid (NFL) behavior with emergent SO(5) symmetry. Here, through a detailed bosonization and refermionization solution, we push forward our previous work and provide a consistent and complete description of the various exotic properties and phase diagram. A unique NFL phase emerges from the presence of an uncoupled Majorana fermion from the flavor sector, whereas Fermi liquid-like susceptibilities result from the gapping out of a pair of Majorana fermions from the spin and flavor sectors. Other properties, such as a scaling of the conductance, stability under channel or spin-symmetry breaking, and a reappearance of NFL behavior upon breaking the particle-hole symmetry, are all accounted for by a renormalization group treatment of the refermionized Majorana model.
- Received 17 March 2021
- Revised 29 April 2021
- Accepted 29 April 2021
DOI:https://doi.org/10.1103/PhysRevB.103.195131
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