Emergence of exceptional points and their spectroscopic signature in a Dirac semimetal–dirty superconductor heterojunction

We theoretically investigate the emergence of non-hermitian physics at heterojunction a type-II Dirac semi-metal (DSM) and dirty superconductor (DSC). The non-hermiticity is introduced in DSM through self-energy term incorporated via dirtiness superconducting material. This causes spectra effective Hamiltonian to become complex, which gives rise appearance exceptional points (EPs). complex self energy, apart from having frequency dependence, also acquires spatial dependence as well, unique can provide interesting effects related spectral function analysis. At an appropriate distance normal metal-superconductor junction DSC, degeneracies appear single point splits into two EPs. In analysis, EPs, Fermi-arc like structure emerges, connects results discussed here are distinctive possibly be realized spectroscopy measurements.