Schwinger effect in a symmetry protected topological phase

The Schwinger effect, classically understood as the particle-antiparticle pair creation in electric fields, has a many-body analog in Mott insulators where doublon-hole pairs lead to dielectric breakdown [1,2]. In this talk, we extend this concept to systems in the symmetry protected topological (SPT) phase. Our focus centers on the S=1 1D Heisenberg model within the Haldane phase under spin-electric fields (or gradient magnetic fields). We'll discuss how these fields give rise to the formation of up and down triplon pairs, leading to an intriguing non-linear generation of spin current. Beyond the creation mechanism, we'll also explore the ramifications for SPT order, including insights into the entanglement spectrum.

[1] T. Oka, R. Arita and H. Aoki, Phys. Rev. Lett. 91, 066406 (2003)

[2] T. Oka, Phys. Rev. B 86, 075148 (2012)