Distinctive electronic and spin structures at the oppositely polarized ferroelectric BiAlO3(0001) surfaces

Electrostatic Modulation and Mechanism of the Electronic Properties of Monolayer MoS2 via Ferroelectric BiAlO3(0001) Polar Surfaces

“…In addition, as mentioned in the introduction, bulk BAO is believed to be an attractive ferroelectric Rashba semiconductor owing to the coexistence and coupling of bulk Rashba spinsplitting and ferroelectricity. 24 In our former report, 25 due to the existence of the heavy element Bi, the BAO(0001) surfaces were also found to exhibit distinctive Rashba−Dresselhaus spin-splittings. It is therefore necessary to explore the influence of SOC on the obtained results and conclusions.…”

“…It can be observed that after full structure relaxation, the BAO Z+ substrate is still terminated with the −Al−O 3 −Bi atomic layer (as shown in Figure 2a), which is the same as the initial thermodynamically preferred BAO Z+ surface termination without MoS 2 adsorption. 22,25 Such information indicates that the adsorption of MoS 2 has no significant influence on the atomic structures of the BAO Z+ surface. Similar conclusions can also be obtained for the relaxed MoS 2 /BAO Z+↓ heterostructure (as shown in Figure 2b).…”

“…Importantly, the dipole correction was turned on to counteract the interaction between periodic slab images . Due to the existence of a prominent Rashba–Dresselhaus spin-splitting in the BAO(0001) polar surface and bulk, , the influence of the spin–orbit coupling (SOC) on the obtained results and conclusions was also investigated.…”

“…In addition, a recent theoretical study indicated that due to the coexistence and coupling of bulk Rashba spin-splitting and ferroelectricity, bulk BAO can be an attractive ferroelectric Rashba semiconductor. Note that in our previous reports , regarding BAO(0001) polar surfaces, the thermodynamic surface phase diagram and the corresponding electronic properties and spin textures were determined. It was found that the thermodynamically preferred positive (Z+) and negative (Z−) polar surfaces are terminated by the −Al–O 3 –Bi atomic layer and the −O 3 –Bi 2 layer, respectively.…”

Comparative density functional studies of BiMO3 polymorphs (M = Al, Ga, In) based on LDA, GGA, and meta-GGA functionals

“…In particular, the coexistence of large spin-orbit coupling with broken space inversion symmetry leads to the formation of the reversible spin texture in ferroelectric BiAlO 3 and BiInO 3 . [23][24][25] On the other hand, polar phases were found in BiGaO 3 -BiMO 3 (M = Cr, Mn, Fe) solid solutions, which make them promising candidates for multiferroics. 15,17,26 For instance, the rhombohedral R3c and monoclinic Cm phases were observed in both the bulk BiGa x Fe 1Àx O 3 and BiGa x Cr 1Àx O 3 and BiGa x Fe 1Àx O 3 thin films.…”