  Doped Iron Chalcogenide (FeCh) superconductors are extensively studied in the
context of topological superconductivity. However, the evidence of topological
surface states in electrical transport measurements of the doped FeCh system is
yet warranted. In the present letter, we performed angle-dependent magneto
transport measurements on a single crystal of a doped FeCh system, i.e.,
FeSe$_{0.5}$Te$_{0.5}$. A non-saturating linear magnetoresistance (MR) has been
observed under the magnetic field up to 14 T in the normal state of
FeSe$_{0.5}$Te$_{0.5}$. The MR is shown to possess anisotropy, which indicates
the presence of topological surface states in FeSe$_{0.5}$Te$_{0.5}$.
Angle-dependent Magneto-conductivity (MC) at low magnetic fields has been
modelled by Hikami Larkin Nagaoka (HLN) formalism, which shows the presence of
weak antilocalization (WAL) effect in FeSe$_{0.5}$Te$_{0.5}$. The observed WAL
effect is found to be 2D in nature through angle-dependent magneto transport
measurements. Theoretical calculations based on Density Functional Theory (DFT)
are also performed to get more confidence on the presence of topological
surface states in FeSe$_{0.5}$Te$_{0.5}$.
