Quantum inverse scattering method
In quantum physics, the quantum inverse scattering method, similar to the closely related algebraic Bethe ansatz, is a method for solving integrable models in 1+1 dimensions, introduced by Leon Takhtajan and L. D. Faddeev in 1979. It can be viewed as a quantized version of the classical inverse scattering method pioneered by Norman Zabusky and Martin Kruskal used to investigate the Korteweg–de Vries equation and later other integrable partial differential equations.
Source: Wikipedia — Quantum inverse scattering method (CC BY-SA 4.0)