Topological features of ground states and topological solitons in generalized Su-Schrieffer-Heeger models using generalized time-reversal, particle-hole, and chiral symmetries

Probing the nature of charge carriers in one-dimensional conjugated polymers: a review of the theoretical models, experimental trends, and thermoelectric applications

“…The solitons and anti-solitons are correlated with the energy state ψ 0 with E 0 = 0, which can drive them to propagate along the one-dimensional conjugated backbone without changing their shape, acting as topological solitons. 45…”

“…The solitons and anti-solitons are correlated with the energy state c 0 with E 0 = 0, which can drive them to propagate along the one-dimensional conjugated backbone without changing their shape, acting as topological solitons. 45 However, quasiparticles such as solitons and anti-solitons can only exist in conjugated polymers with a degenerate ground state, e.g., polyacetylene, for the geometric alternation of single and double bonds in the polymer backbone results in the ground states with the same energy. 46 For the conjugated polymers with non-degenerate ground states, i.e., polythiophene, polypyrrole, and polyaniline, the coupling modes of charges to the underlying lattice structures may behave differently.…”

Collision, mechanism, and $Z_4$ operation among chiral and nonchiral kinks in coupled double-field $ϕ^4$ model

“…For the 1D case, three types of chiral solitons were realized in the indium atomic wire, and chirality switching between chiral and nonchiral solitons via collision was also demonstrated in the same physical system [58,59]. This system is described by the double Peierls chain model, which corresponds to the coupled Jackiw-Rebbi field theory composed of two fermion fields and two boson fields [58,[60][61][62][63]. Before these experiments, there were a few theoretical works [30][31][32][33][34][35] about the coupled two field models.…”

Topological and trivial domain wall states in engineered atomic chains

“…Their system allows to experimentally tune the domain wall states using atom manipulation by the tip of a scanning tunneling microscope (STM). They have realized topological domain wall states of two prototypical one-dimensional models such as trimer 3 and coupled dimer chains [4][5][6][7][8] . However, they did not distinguish trivial domain wall states 9 from topological ones in their models.…”

“…By coupling two SSH chains, we introduce a coupled dimer chain with four ground states where topological chiral domain wall states can emerge when one of two SSH subchains has an interface between topologically distinct Zak phases [5][6][7][8] . However, the defective domain wall AA → AB (Fig.…”