Critical phase boundary and finite-size fluctuations in
Su-Schrieffer-Heeger model with random inter-cell couplings
- URL: http://arxiv.org/abs/2111.15500v2
- Date: Sat, 12 Feb 2022 00:09:31 GMT
- Title: Critical phase boundary and finite-size fluctuations in
Su-Schrieffer-Heeger model with random inter-cell couplings
- Authors: D. S. Shapiro, S. V. Remizov, A. V. Lebedev, D. V. Babukhin, R. S.
Akzyanov, A. A. Zhukov, L. V. Bork
- Abstract summary: In this work, we investigate a special sort of a disorder when inter-cell hopping amplitudes are random.
Using a definition for $mathbbZ$-topological invariant $nuin 0; 1$ in terms of a non-Hermitian part of the total Hamiltonian, we calculate $langlenurangle averaged by random realizations.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: A dimerized fermion chain, described by Su-Schrieffer-Heeger (SSH) model, is
a well-known example of 1D system with a non-trivial band topology. An
interplay of disorder and topological ordering in the SSH model is of a great
interest owing to experimental advancements in synthesized quantum simulators.
In this work, we investigate a special sort of a disorder when inter-cell
hopping amplitudes are random. Using a definition for
$\mathbb{Z}_2$-topological invariant $\nu\in \{ 0; 1\}$ in terms of a
non-Hermitian part of the total Hamiltonian, we calculate $\langle\nu\rangle$
averaged by random realizations. This allows to find (i) an analytical form of
the critical surface that separates phases of distinct topological orders and
(ii) finite size fluctuations of $\nu$ for arbitrary disorder strength.
Numerical simulations of the edge modes formation and gap suppression at the
transition are provided for finite-size system. In the end, we discuss a
band-touching condition derived within the averaged Green function method for a
thermodynamic limit.
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