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Spectral flow of non-hermitian Heisenberg spin chain with complex twist

T. Fukui·N. Kawakami
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Abstract

We investigate the spectral flow of the integrable non-hermitian Heisenberg spin chain under boundary conditions with complex twist angle. It is shown that the period of the spectral flow is $4π$ up to a certain critical imaginary twist, beyond which the period jumps successively to higher values. We argue that this phenomenon caused by non-hermitian properties of the system is closely related to the metal-insulator transition caused by non-hermitian hoppings for the one-dimensional insulator.

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T. Fukui, N. Kawakami. 1998-02-12. Spectral flow of non-hermitian Heisenberg spin chain with complex twist. https://doi.org/10.1016/s0550-3213(98)00150-3

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