Scattering dynamics and boundary states of a non-Hermitian Dirac equation

We study a non-Hermitian variant of the (2+1)-dimensional Dirac wave equation, which hosts a real energy spectrum with pairwise-orthogonal eigenstates. In the spatially uniform case, the Hamiltonian's non-Hermitian symmetries allow its eigenstates to be mapped to a pair of Hermitian Dirac s...

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Main Authors: Terh, Yun Yong, Banerjee, Rimi, Xue, Haoran, Chong, Yidong
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2023
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Online Access:https://hdl.handle.net/10356/170176
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Institution: Nanyang Technological University
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spelling sg-ntu-dr.10356-1701762023-09-04T15:34:50Z Scattering dynamics and boundary states of a non-Hermitian Dirac equation Terh, Yun Yong Banerjee, Rimi Xue, Haoran Chong, Yidong School of Physical and Mathematical Sciences Centre for Disruptive Photonic Technologies (CDPT) Science::Physics Science::Physics::Optics and light Boundary State Dirac's Equation We study a non-Hermitian variant of the (2+1)-dimensional Dirac wave equation, which hosts a real energy spectrum with pairwise-orthogonal eigenstates. In the spatially uniform case, the Hamiltonian's non-Hermitian symmetries allow its eigenstates to be mapped to a pair of Hermitian Dirac subsystems. When a wave is transmitted across an interface between two spatially uniform domains with different model parameters, an anomalous form of Klein tunneling can occur, whereby reflection is suppressed while the transmitted flux is substantially higher or lower than the incident flux. The interface can even function as a simultaneous laser and coherent perfect absorber. Remarkably, the violation of flux conservation occurs entirely at the interface, as no wave amplification or damping takes place in the bulk. Moreover, at energies within the Dirac mass gaps, the interface can support exponentially localized boundary states with real energies. These features of the continuum model can also be reproduced in non-Hermitian lattice models. National Research Foundation (NRF) Published version This work was supported by the National Research Foundation (NRF), Singapore under its Competitive Research Programmes NRF-CRP23-2019-0005 and NRF-CRP23-2019- 0007, and NRF Investigatorship NRF-NRFI08-2022-0001. 2023-08-31T00:52:19Z 2023-08-31T00:52:19Z 2023 Journal Article Terh, Y. Y., Banerjee, R., Xue, H. & Chong, Y. (2023). Scattering dynamics and boundary states of a non-Hermitian Dirac equation. Physical Review B, 108(4), 045419-. https://dx.doi.org/10.1103/PhysRevB.108.045419 1098-0121 https://hdl.handle.net/10356/170176 10.1103/PhysRevB.108.045419 2-s2.0-85166774519 4 108 045419 en NRF-CRP23-2019-0005 NRF-CRP23-2019- 0007 NRF-NRFI08-2022-0001 Physical Review B © 2023 American Physical Society. All rights reserved. This paper was published in Physical Review B and is made available with permission of American Physical Society. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Science::Physics
Science::Physics::Optics and light
Boundary State
Dirac's Equation
spellingShingle Science::Physics
Science::Physics::Optics and light
Boundary State
Dirac's Equation
Terh, Yun Yong
Banerjee, Rimi
Xue, Haoran
Chong, Yidong
Scattering dynamics and boundary states of a non-Hermitian Dirac equation
description We study a non-Hermitian variant of the (2+1)-dimensional Dirac wave equation, which hosts a real energy spectrum with pairwise-orthogonal eigenstates. In the spatially uniform case, the Hamiltonian's non-Hermitian symmetries allow its eigenstates to be mapped to a pair of Hermitian Dirac subsystems. When a wave is transmitted across an interface between two spatially uniform domains with different model parameters, an anomalous form of Klein tunneling can occur, whereby reflection is suppressed while the transmitted flux is substantially higher or lower than the incident flux. The interface can even function as a simultaneous laser and coherent perfect absorber. Remarkably, the violation of flux conservation occurs entirely at the interface, as no wave amplification or damping takes place in the bulk. Moreover, at energies within the Dirac mass gaps, the interface can support exponentially localized boundary states with real energies. These features of the continuum model can also be reproduced in non-Hermitian lattice models.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Terh, Yun Yong
Banerjee, Rimi
Xue, Haoran
Chong, Yidong
format Article
author Terh, Yun Yong
Banerjee, Rimi
Xue, Haoran
Chong, Yidong
author_sort Terh, Yun Yong
title Scattering dynamics and boundary states of a non-Hermitian Dirac equation
title_short Scattering dynamics and boundary states of a non-Hermitian Dirac equation
title_full Scattering dynamics and boundary states of a non-Hermitian Dirac equation
title_fullStr Scattering dynamics and boundary states of a non-Hermitian Dirac equation
title_full_unstemmed Scattering dynamics and boundary states of a non-Hermitian Dirac equation
title_sort scattering dynamics and boundary states of a non-hermitian dirac equation
publishDate 2023
url https://hdl.handle.net/10356/170176
_version_ 1779156572903047168