Subdiffusive Phases in Open Clean Long-Range Systems

We show that a one-dimensional ordered fermionic lattice system with power-law-decaying hopping, when connected to two baths at its two ends with different chemical potentials at zero temperature, features two phases showing subdiffusive scaling of conductance with system size. These phases have no analogues in the isolated system (i.e., in absence of the baths) where the transport is perfectly ballistic. In the open system scenario, interestingly, there occurs two chemical-potential-driven subdiffusive to ballistic phase transitions at zero temperature. We discuss how these phase transitions, to our knowledge, are different from all the known nonequilibrium quantum phase transitions. We provide a clear understanding of the microscopic origin of these phases and argue that the subdiffusive phases are robust against the presence of arbitrary number-conserving many-body interactions in the system. These phases showing subdiffusive scaling of conductance with system size in a two-terminal setup are therefore universal properties of all ordered one-dimensional number-conserving fermionic systems with power-law-decaying hopping at zero temperature.

Automated summary

This study reveals that a one-dimensional ordered fermionic lattice system connected to two baths with different chemical potentials at zero temperature exhibits two phases of subdiffusive conductance scaling with system size, unlike the perfectly ballistic transport in the isolated system. Interestingly, there are two chemical-potential-driven subdiffusive to ballistic phase transitions at zero temperature in the open system scenario.