Searches for non-MSSM top/bottom quark partners with the ATLAS detector at the LHC

The naturalness is a paradigm for theories beyond the Standard Model (BSM), incorporating mechanism to cancel mass divergence for the Higgs boson. The presence of fermionic top/bottom quark partners, usually referred to as vector-like quarks (VLQs), may be an important ingredient for such mechanism in non-SUSY scenarios. Searches for vector-like quarks have been performed in various final states at the ATLAS experiment. This talk highlights recent VLQ searches at ATLAS with LHC Run 1 data. First LHC Run-2 results will be included if available.