Fig. 2: Finite-size effect of MnBi2Te4 thin films.
From: Tunable dynamical magnetoelectric effect in antiferromagnetic topological insulator MnBi2Te4 films
a The evolution of the band structure of the 12-SL MnBi2Te4 thin film as a function of the strength of the SOC λ/λ0. b The evolution of the energy gap with the SOC strength. The energy gap first goes smaller and then goes larger without exactly closing. It is clear to see a minimum energy gap when increasing the SOC, which corresponds to 2∣m5∣ (the \({\mathcal{P}}\), \({\mathcal{S}}\)-breaking mass). c,d The mass m5 versus the thickness of MnBi2Te4 (red) and Mn2Bi2Te5 (blue) thin films. N presents the number of bi-SLs of MnBi2Te4 films or (nonuple layers)NLs of Mn2Bi2Te5 films.
