Grassmann time-evolving matrix product operators for fermionic impurities coupled to a superconducting bath
The Nambu-GTEMPO method extends Grassmann time-evolving matrix product operators to solve fermionic impurity problems involving superconducting baths. By using Bogoliubov transformations, it handles the bath's superconducting nature analytically, allowing for accurate calculations of correlation functions in both equilibrium and non-equilibrium systems without sampling noise.