Antiferromagnetic topological insulating state in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Tb</mml:mi><mml:mrow><mml:mn>0.02</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi>Bi</mml:mi><mml:mrow><mml:mn>1.08</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi>Sb</mml:mi><mml:mrow><mml:mn>0.9</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi mathvariant="normal">S</mml:mi></mml:mrow></mml:math> single crystals

Topological insulators are emerging materials with insulating bulk and symmetry protected nontrivial surface states. One of the most fascinating transport behaviors in a topological insulator is quantized anomalous Hall insulator, which has been observed magnetic-topological-insulator-based devices. In this work, we report successful doping rare earth element Tb into ${\mathrm{Bi}}_{1.08}{\mathrm{Sb}}_{0.9}{\mathrm{Te}}_{2}\mathrm{S}$ single crystals, moments antiferromagnetically ordered below $\ensuremath{\sim}10$ K. Benefiting from in-bulk-gap Fermi level, behavior dominant by states $\ensuremath{\sim}150$ At low temperatures, strong Shubnikov--de Haas oscillations observed, exhibit 2D-like behavior. The long range magnetic ordering doped crystal provides an ideal platform for quantum studies potential applications.