  The ratio of shear viscosity over entropy density in low energy heavy-ion
collision has been calculated by using the Green-Kubo method in the framework
of an extended quantum molecular dynamics model. After the system almost
reaching a local equilibration for a head-on $^{40}$Ca+$^{100}$Mo collision,
thermodynamic and transport properties are extracted. Meanwhile, iso-vector
giant dipole resonance (IVGDR) of the collision system is also studied. By the
Gaussian fits to the IVGDR photon spectra, the peak energies of IVGDR are
extracted at different incident energies. The result shows that the IVGDR peak
energy has a positive correlation with the ratio of shear viscosity over
entropy density. This is a quantum effect and indicates a difference between
nuclear matter and classical fluid.
