AbstractBi$$_{1-x}$$
1
-
x
Sb$$_x$$
x
is a topological insulator (TI) for $$x \approx 0.03$$
x
≈
0.03
–0.20. Close to the Topological phase transition at $$x = 0.03$$
x
=
0.03
, a magnetic field induced Weyl semi-metal (WSM) state is stabilized due to the splitting of the Dirac cone into two Weyl cones of opposite chirality. A signature of the Weyl state is the observation of a Chiral anomaly [negative longitudinal magnetoresistance (LMR)] and a violation of the Ohm’s law (non-linear $$I{-}V$$
I
-
V
). We report the unexpected discovery of Chiral anomaly-like features in the whole range ($$x = 0.032, 0.072, 0.16$$
x
=
0.032
,
0.072
,
0.16
) of the TI state. This points to a field induced WSM state in an extended x range and not just near the topological transition at $$x = 0.03$$
x
=
0.03
. Surprisingly, the strongest Weyl phase is found at $$x = 0.16$$
x
=
0.16
with a non-saturating negative LMR much larger than observed for $$x = 0.03$$
x
=
0.03
. The negative LMR vanishes rapidly with increasing angle between B and I. Additionally, non-linear I–V is found for $$x = 0.16$$
x
=
0.16
indicating a violation of Ohm’s law. This unexpected observation of a strong Weyl state in the whole TI regime in Bi$$_{1-x}$$
1
-
x
Sb$$_x$$
x
points to a gap in our understanding of the detailed crystal and electronic structure evolution in this alloy system.