Detecting quantum phase transitions in the quasistationary regime of Ising chains


Recently, single-site observables have been shown to be useful for probing critical slowing down in sudden quench dynamics Dağ et al., Phys. Rev. B 107, L121113 (2023). Here, we demonstrate the potential of single-site magnetization as a probe of quantum phase transitions in integrable and nonintegrable transverse-field Ising chains (TFIC). We analytically prove the requirement of zero modes for the quasistationary regime to emerge at a probe site near the edge, and show how this regime gives rise to a nonanalytic behavior in the dynamical order profiles. Our $t$-DMRG calculations verify the results of the quench mean-field theory for near-integrable TFIC both with finite-size and finite-time scaling analyses. We find that both finite-size and finite-time analyses suggest a dynamical critical point for a strongly nonintegrable and locally connected TFIC. We finally demonstrate the presence of a quasistationary regime in the power-law interacting TFIC, and extract local dynamical order profiles for TFIC in the long-range Ising universality class with algebraic light cones.

Physical Review B 107, 094432
Published 28 March 2023
Philipp Uhrich
PhD Student (2019 – 2023)
Jad C. Halimeh
Postdoc (2019 – 2021)
Now Senior Postdoc at LMU München