Asymmetric transmission through a flux-controlled non-Hermitian scattering center

Abstract

We study the possibility of asymmetric transmission induced by a non-Hermitian scattering center embedded in a one-dimensional waveguide, motivated by the aim of realizing quantum diode in a non-Hermitian system. It is shown that a $\mathcal{P}\mathcal{T}$ symmetric non-Hermitian scattering center always has symmetric transmission although the dynamics within the isolated center can be unidirectional, especially at its exceptional point. We propose a concrete scheme based on a flux-controlled non-Hermitian scattering center, which comprises a non-Hermitian triangular ring threaded by an Aharonov-Bohm flux. The analytical solution shows that such a complex scattering center acts as a diode at the resonant energy level of the spectral singularity, exhibiting perfect unidirectionality of the transmission. The connections between the phenomena of the asymmetric transmission and reflectionless absorption are also discussed.

6 pages, 5 figures

References in corpus (9)

• Exactly solvable PT-symmetric Hamiltonian having no Hermitian counterpart
• Interface between Hermitian and non-Hermitian Hamiltonians in a model calculation
• Scattering theory with localized non-Hermiticities
• Spectral singularities in PT-symmetric periodic finite-gap systems
• Scattering theory using smeared non-Hermitian potentials
• Fundamental length in quantum theories with PT-symmetric Hamiltonians
• Exceptional points and Bloch oscillations in non-Hermitian lattices with unidirectional hopping
• Fundamental length in quantum theories with PT-symmetric Hamiltonians II: The case of quantum graphs
• Transmission phase lapse in the non-Hermitian Aharonov-Bohm interferometer near the spectral singularity

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• Non-Hermitian interferometer: Unidirectional amplification without distortion
• Quantum transport in non-Hermitian impurity array
• Work statistics in non-Hermitian evolutions with Hermitian endpoints
• Spectral singularity in composite systems and simulation of a resonant lasing cavity