학술논문
Non-Local Order Parameters as a Probe for Phase Transitions in the Extended Fermi-Hubbard Model
Document Type
Working Paper
Author
Source
Eur. Phys. J. Spec. Top. (2017) 226: 2697
Subject
Language
Abstract
The Extended Fermi-Hubbard model is a rather studied Hamiltonian due to both its many applications and a rich phase diagram. Here we prove that all the phase transitions encoded in its one dimensional version are detectable via non-local operators related to charge and spin fluctuations. The main advantage in using them is that, in contrast to usual local operators, their asymptotic average value is finite only in the appropriate gapped phases. This makes them powerful and accurate probes to detect quantum phase transitions. Our results indeed confirm that they are able to properly capture both the nature and the location of the transitions. Relevantly, this happens also for conducting phases with a spin gap, thus providing an order parameter for the identification of superconducting and paired superfluid phases
Comment: 7 pages, 3 figures; Submitted to EPJ Special Topics, Quantum Gases and Quantum Coherence
Comment: 7 pages, 3 figures; Submitted to EPJ Special Topics, Quantum Gases and Quantum Coherence