Charge-Spin-Flavor separation in quantum impurity problems

The Kondo problem is an ideal example of spin-charge separation at all energies. In multichannel versions of the problem, an additional internal degree of freedom, sometimes called flavor, labels the different channels and (partially) gets decoupled as well. Following a critical revision of the procedures for bosonization and debosonization of quantum impurity models [1,2], we study the spin-flavor interplay in detail by comparing refermionized versions of the model done following different schemes. We find that non-equilibrium probes can be more sensitive to the spin-flavor interplay at the strong-coupling fixed point as compared to thermodynamic measurements.

[1] N. Shah and C.J. Bolech, Phys. Rev. B 93, 085440 (2016)

[2] C.J. Bolech and N. Shah, Phys. Rev. B 93, 085441 (2016)