  The journey through the nontrivial band topology beyond the conventional band
structure has resulted in the recent discovery of three-dimensional Dirac
semimetal phase in Na$_{3}$Bi and Cd$_{3}$As$_{2}$. The bulk state of which is
semi-metallic obeying linear energy dispersion, while the surface state is
topology protected Fermi arc. Due to the unique band topology, they show
different exotic electronic properties of both fundamental and technological
interest. From electrical and thermal transport measurements, we have
demonstrated a remarkable violation of Wiedemann-Franz law (WFL) under
application of magmatic field in Cd$_{3}$As$_{2}$ and the violation becomes
more and more drastic with increasing magnetic field strength. Whereas the
validity of WFL is the key feature of Landau Fermi-liquid theory in metal, the
notion of quasiparticles is the building block to this theory. This implies
that the fundamental concept of Landau quasiparticle no longer holds in
Cd$_{3}$As$_{2}$ in presence of magnetic field. The continuous break down of
Landau quasiparticle framework with field introduces a concept of field induced
quantum critical point (QCP) as in the case of heavy fermion compounds
YbRh$_{2}$Si$_{2}$, Sr$_{3}$Ru$_{2}$O$_{7}$, etc.
