Universality at work  the local sineGordon model, lattice fermions, and quantum circuits
Abstract
We review the intriguing manybody physics resulting out of the interplay of a single, local impurity and the twoparticle interaction in a onedimensional Fermi system. Even if the underlying homogeneous correlated system is taken to be metallic, this interplay leads to an emergent quantum phase transition between metallic and insulating states. We show that the zero temperature critical point and the universal lowenergy physics associated to it, is realized in two different models, the field theoretical local sineGordon model and spinless fermions on a lattice with nearestneighbor hopping and twoparticle interaction, as well as in an experimental setup consisting of a highly tunable quantum circuit. Despite the different highenergy physics of the three systems the universal lowenergy scaling curves of the conductance as a function of temperature agree up to a very high precision without any free parameter. Overall this provides a convincing example of how emergent universality in complex systems originating from a common underlying quantum critical point establishes a bridge between different fields of physics. In our case between field theory, quantum manybody theory of correlated Fermi systems, and experimental circuit quantum electrodynamics.
 Publication:

European Physical Journal Special Topics
 Pub Date:
 February 2020
 DOI:
 10.1140/epjst/e20199001175
 arXiv:
 arXiv:1912.04578
 Bibcode:
 2020EPJST.229..663A
 Keywords:

 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 version as accepted for publication in EPJST