Journal or Book Title
Physics Review Letters
We study a single polaron in the Su-Schrieffer-Heeger (SSH) model using four different techniques (three numerical and one analytical). Polarons show a smooth crossover from weak to strong coupling, as a function of the electron-phonon coupling strength λ, in all models where this coupling depends only on phonon momentum q. In the SSH model the coupling also depends on the electron momentum k; we find it has a sharp transition, at a critical coupling strength λc, between states with zero and nonzero momentum of the ground state. All other properties of the polaron are also singular at λ=λc. This result is representative of all polarons with coupling depending on k and q, and will have important experimental consequences (e.g., in angle-resolved photoemission spectroscopy and conductivity experiments).
Marchand, D; De Filippis, G; Cataudella, V; Berciu, M; Nagaosa, N; Prokof'ev, Nikolai; Mishchenko, A; and Stamp, P, "Sharp Transition for Single Polarons in the One-Dimensional Su-Schrieffer-Heeger Model" (2010). Physics Review Letters. 1164.
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