Magnetic and transport properties in the magnetic topological insulators MnBi2Te4(Bi2Te3)n ( n=1,2 )

The observation of quantized anomalous Hall conductance in the forced ferromagnetic state of $\mathrm{MnB}{\mathrm{i}}_{2}\mathrm{T}{\mathrm{e}}_{4}$ thin flakes has attracted much attention. However, a strong magnetic field is needed to fully polarize the magnetic moments due to the large antiferromagnetic interlayer exchange coupling. Here, we reported the magnetic and electrical transport properties of the magnetic van der Waals $\mathrm{MnB}{\mathrm{i}}_{2}\mathrm{T}{\mathrm{e}}_{4}{(\mathrm{B}{\mathrm{i}}_{2}\mathrm{T}{\mathrm{e}}_{3})}_{n}$ ($n=1,2$) single crystals, in which the interlayer antiferromagnetic exchange coupling is greatly suppressed with the increase of the separation layers $\mathrm{B}{\mathrm{i}}_{2}\mathrm{T}{\mathrm{e}}_{3}$. $\mathrm{MnB}{\mathrm{i}}_{4}\mathrm{T}{\mathrm{e}}_{7}$ and $\mathrm{MnB}{\mathrm{i}}_{6}\mathrm{T}{\mathrm{e}}_{10}$ show weak antiferromagnetic transition at 12.3 and 10.5 K, respectively. The ferromagnetic hysteresis was observed at low temperature for both of the crystals, which is quite crucial for realizing the quantum anomalous Hall effect without external magnetic field. Our work indicates that $\mathrm{MnB}{\mathrm{i}}_{2}\mathrm{T}{\mathrm{e}}_{4}{(\mathrm{B}{\mathrm{i}}_{2}\mathrm{T}{\mathrm{e}}_{3})}_{n}$ ($n=1,2$) provides an ideal platform to investigate the rich topological phases with their two-dimensional limits.