Title:	Anomalous dynamical response of non-Hermitian topological phases
Authors:	Nehra, Ritu Roy, Dibyendu
Issue Date:	27-Mar-2024
Publisher:	American Physical Society
Citation:	Physical Review B, 2024, Vol. 109, p094311
Abstract:	Composite topological phases with intriguing topology like Möbius strips emerge in sublattice symmetric non-Hermitian systems due to spontaneous breaking of time-reversal symmetry at some parameter regime. While these phases have been characterized by nonadiabatic complex geometric phases of multiple participating complex bands, the physical properties of these phases remain largely unknown. We explore the dynamical response of these phases by studying Loschmidt echo from an initial state of the Hermitian Su-Schrieffer-Heeger (SSH) model, which is evolved by a non-Hermitian SSH Hamiltonian after a sudden quench in parameters. Topology-changing quenches display nonanalytical temporal behavior of return rates (logarithm of the Loschmidt echo) for the non-Hermitian SSH Hamiltonian in the trivial, Möbius, and topological phase. Moreover, the dynamical topological order parameter appears only at one side of the Brillouin zone for the Möbius phase case in contrast to both sides of the Brillouin zone for quench by the trivial and topological phase of the non-Hermitian SSH model. The last feature is a dynamical signature of different symmetry constraints on the real and imaginary parts of the complex bands in the Möbius phase.
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/8248
Alternative Location:	https://arxiv.org/abs/2310.12633 https://doi.org/10.1103/PhysRevB.109.094311 https://ui.adsabs.harvard.edu/abs/2023arXiv231012633N/abstract
Copyright:	2024 American Physical Society
Appears in Collections:	Research Papers (TP)

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