Abstract
The ground-state properties of RMnO3 /AMnO3 RMO/AMO heterostructures with R=La,Pr, . . ., a trivalent
rare-earth cation and A=Sr,Ca, . . ., a divalent alkaline cation are studied using a two-orbital doubleexchange
model including the superexchange coupling and Jahn-Teller lattice distortions. To describe the
charge transfer across the interface, the long-range Coulomb interaction is taken into account at the mean-field
level, by self-consistently solving the Poisson’s equation. The calculations are carried out numerically on finite
clusters. We find that the state stabilized near the interface of the heterostructure is similar to the state of the
bulk compound R,AMO at electronic density close to 0.5. For instance, a charge and orbitally ordered CE
state is found at the interface if the corresponding bulk R,AMO material is a narrow-to-intermediate bandwidth
manganite. But instead the interface regime accommodates an A-type antiferromagnetic state with a
uniform x2−y2 orbital order, if the bulk R,AMO corresponds to a wide bandwidth manganite. We argue that
these results explain some of the properties of long-period RMOm/ AMOn superlattices, such as
PrMnO3m/ CaMnO3n and LaMnO3m/ SrMnO3n. We also remark that the intermediate states in between
the actual interface and the bulklike regimes of the heterostructure are dependent on the bandwidth and the
screening of the Coulomb interaction. In these regions of the heterostructures, states are found that do not have
an analog in experimentally known bulk phase diagrams. These new states of the heterostructures provide a
natural interpolation between magnetically ordered states that are stable in the bulk at different electronic
densities.
