A search for the direct production of charginos
and neutralinos in final states with at least two hadronically
decaying tau leptons is presented. The analysis uses a dataset
of pp collisions corresponding to an integrated luminosity of
36.1 fb−1
, recorded with the ATLAS detector at the Large
Hadron Collider at a centre-of-mass energy of 13 TeV. No significant
deviation from the expected Standard Model background
is observed. Limits are derived in scenarios of χ˜
+
1 χ˜
−
1
pair production and of χ˜
±
1 χ˜
0
2 and χ˜
+
1 χ˜
−
1 production in simplified
models where the neutralinos and charginos decay
solely via intermediate left-handed staus and tau sneutrinos,
and the mass of the τ˜L state is set to be halfway between the
masses of the χ˜
±
1 and the χ˜
0
1 . Chargino masses up to 630 GeV
are excluded at 95% confidence level in the scenario of direct
production of χ˜
+
1 χ˜
−
1 for a massless χ˜
0
1 . Common χ˜
±
1 and χ˜
0
2
masses up to 760 GeV are excluded in the case of production
of χ˜
±
1 χ˜
0
2 and χ˜
+
1 χ˜
−
1 assuming a massless χ˜
0
1 . Exclusion limits
for additional benchmark scenarios with large and small
mass-splitting between the χ˜
±
1 and the χ˜
0
1 are also studied
by varying the τ˜L mass between the masses of the χ˜
±
1 and
the χ˜
0
1 .