Energy Spectrum And Tunneling Properties Of PT Symmetric Non-Hermitian Complex Quantum Dot Structures

Non-Hermi systems with PT-symmetry can still have real eigen-spectrum spectra,and many related conclusions have been verified in experiments such as acoustics and optics.Therefore,such systems have received much attention in recent years.The PT-symmetric non-Emmy system opens up new horizons for researchers in experiments and applications,and has begun to appear in all areas of physics.Based on this background,the paper studies the transport properties,eigenbeam spectra and topological properties of one-dimensional PT-symmetric non-Ermian systems.The basic ideas of the article are as follows:Firstly,based on the long-chain of one-dimensional infinitely long dimers,two impurity sites with PT-symmetric complex potentials are coupled on both sides.The analytic formula of the tunneling function of this model is solved by the scattering matrix method,and the influence of the PT-symmetric complex potential on the scattering behavior of the non-Hermi system is studied.It is found that the PTsymmetric complex potential can cause Fano resonance,standard anti-resonance,and weakening scattering in the scattering behavior.Subsequently,a semi-infinite long monoatomic chain was introduced in the first model to partially replace the dimer chain of the original model.The final model is a one-dimensional long chain with a semiinfinite long monoatomic chain coupled with a semi-infinite long dimer chain.The nonequilibrium Green's function method is used to solve the tunneling function of the model,and numerical analysis and mapping are performed.After comparing the tunneling function images of the two models under the same parameter structure,we found that the introduction of the single atom chain mainly affects the peak value of the tunneling function.When the coupling of the right dimer chain to the impurity is cut off,since the impurity point is not strengthened,the influence of the introduction of the left single atom chain on the tunneling function is insignificant in the process of being transmitted to the right side.Secondly,the intrinsic energy and tunneling function spectrum of one-dimensional quantum chains of coupled quantum dots are studied.It is found in the numerical results that when the PT-symmetric complex potential can be introduced into the secondary quantum dots in pairs,the originally degenerate energy levels in the intrinsic energy are destroyed.However,when the complex potential can be further increased,it will cause a new secondary degeneracy in the intrinsic energy spectrum,accompanied by the breaking of the PT symmetry,resulting in a non-zero value of the imaginary part of the intrinsic energy.This change does affect the quantum tunneling properties of quantum chains.When the PT-symmetric complex potential is weak,a new set of tunneling function peaks appear in the middle of the tunneling function spectrum.With the degeneration of the new energy level,the degenerate intrinsic energy level and lead decoupling And the corresponding peak disappears in the tunneling function spectrum.Finally,the one-dimensional Extended SSH model of sub-nearest neighbor coupling is studied.It is observed from the energy spectrum that the energy band structure of the Extended SSH model has topological properties,and it has a standard topological mean region(??(?/2,3?/2))and the non-topological mediocrity region(??(-?/2,?/2)),and two Dirac points ?=±?/2 appear at the same time,and the boundary state appears in the topological non-mean region.Next,the PT-symmetric complex potential energy is applied at both ends of the model and at both ends of the cell,and it is observed that the eigenvalue still has a real solution.After applying the PT-ymmetric complex potential energy,the body state of the topological mediocrity region will only occur when the complex potential energy intensity y is greater than the critical value,and the non-zero imaginary eigengen energy appears.In the case of topological non-mean regions,there are two cases:the boundary states always have PT-ymmetry breaking in the presence of complex potential energy,and the non-zero values appear in pairs in the imaginary part of the intrinsic energy;and the postures in the topological non-mean regions Then,like the body state in the topological mediocrity region,PT-ymmetry breaking occurs only when the complex potential energy ? is greater than the critical value.The boundary state wave function is distributed at both ends of the model,and the coupling between the lattice points at both ends and the nonend lattice points is severely weakened.