  In this letter, we provide fundamental insights into the dynamic
transcritical transition process using molecular dynamics simulations. A
transcritical region, which covers three different fluid states, was discovered
as a substitute for the traditional interface. The physical properties, such as
temperature and density, exhibited a highly non-linear distribution in the
transcritical region. Meanwhile, the surface tension was found to exist
throughout the transcritical region, and the magnitude was directly
proportional to $ - \rho \cdot {\nabla ^2}\rho $
