The operator of observable physical quantity in the quantum system must be the Hermitian operator because of the operator of observable physical quantity in the quantum system must be the Hermitian operator.However,researchers have discovered that non-Hermitian operators can also have completely real eigenvalues in non-Hermitian parity-time symmetric systems.Because of this property,the ex-istence of exceptional points has attracted extensive attention.Further study of existence of exceptional points in the non-Hermitian systems,where many interest-ing physical phenomena occur in classical optical systems,such as optical isolation,coherent perfect absorption,unidirectional reflectionlessness,electromagnetically in-duced transparency,and so on.Not only that,the existence of exceptional points in Hermitian and non-Hermitian quantum systems has also aroused people’s attention.Recently,the transport prop-erties of surface plasmonic or photon in metal nanowire was widely investigated.Es-pecially,the unidirectional transportion of surface plasmonic or photon in plasmonic waveguide has been widely studied in non-Hermitian systems,However,the trans-port properties of quantum dots coupled to plamonic waveguide in non-Hermitian systems in two direction has been little investigated.Motivated by the above ideas,we investigated the dual-band unidirectional reflecctionless phenomenon of surface plasmonic is incident in two directions at exceptional points in a non-Hermitian quantum system.The main research content are as follows:(1)We investigate the undirectional reflectionlessness in a non-Hermitian quan-tum system,which consists of two V-type three-level quantum dots coupled to a plasmonic waveguide.The dual-band unidirectional reflectionlessness can be ob-tained at exceptional points by appropriately adjusting the resonance wavelengths of two quantum dots and coupling strengths between the quantum dots and plas-monic waveguide.And the dual-band low undirectional reflection can be realized in the wide range of wavelength(2)Dual-band unidirectional reflectionlessness is investigated in a non-Hermitian quantum system consisting of a two-level and a V-type three-level quantum dots cou-pled to a plasmonic waveguide based on electromagnetically induced transparency-like effect.The results show that the dual-band unidirectional reflectionlessness can be obtained by appropriately adjusting the phase shift between two quantum dots,decay rates of quantum dots,and coupling strengths between quantum dots and plasmonic waveguide.Moreover,the dual-band low unidirectional reflection phe-nomenon can be realized in the wide ranges of decay rates and coupling strengths. |