Responses of the topological surface states to Mn-covered on topological insulators Bi2Se3 film

• Mn atom induces a spin-polarization with local net magnetic moments of 1.730 μB.
• Mn atom breaks the local time reversal symmetry.
• The Dirac cone of the top surface disappears and the Fermi level shifts up to band gaps.
• The Dirac cone of the bottom surface is still alive and shifts downward.

Based on first-principles calculations within density functional theory, we studied the electronic and magnetic properties of Mn-coverd Bi2Se3 film employing spin–orbit coupling (SOC) self-consistently. For the Mn monolayer on the Bi2Se3 film, the energy favored structure is that Mn atoms are buried between top surface Se atoms and the second layer Bi atoms. It induces a spin-polarization with local net magnetic moments of 1.730 μB Mn atom breaks the local time reversal symmetry and the Dirac cone of Mn-covered surface disappears. While the Dirac cone of the Mn free surface is still alive. For the substitution of Mn atom for the outmost-layer Se atom, the electronic structure is similar to the case of the ad-Mn system.