semiclassical

From semi- +‎ classical.

semiclassical (comparative more semiclassical, superlative most semiclassical)

1. (music, of a piece of music) That is classical but has broad, popular appeal.
2. (physics) Of, pertaining to, or being a theory that describes a physical system by dividing it into two parts, one described by classical physics and the other by either relativistic or quantum mechanical physics.
   • 1994, X. Viñas, M. Centelles, M. Durand, P. Schuck, “On the Variational Content of the Wigner-Kirkwood ${\displaystyle \hbar }$ Expansion”, in Carlos Fiolhais, Manuel Fiolhais, Celia Sousa, Jose N Urbano, editors, Proceedings of the International Conference on Many-body Physics, World Scientific, page 392:

     The semiclassical approach to the relativistic theory has been recently worked out by several authors and the ${\displaystyle \hbar ^{2}}$ corrections to the earlier established TF relativistic theory have been derived^17—19.

   • 2020, Bei-Lok B. Hu, Enric Verdaguer, Semiclassical and Stochastic Gravity, Cambridge University Press, page 337,

     Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein—Langevin equation, which has in addition sources due to the noise kernel.

   • 2024, Chaoyuan Zhu, Semiclassical Nonadiabatic Molecular Dynamics, Springer, page 109,

     Of course, the main problem with such semiclassical treatment is to find suitable coordinate[s] in which [a] multidimensional scattering or reaction Schrödinger equation has to be expanded into the^[sic] certain one-dimensional many-state coupled Schrödinger equations like Equation 4.219.