Ferroelectric modulation on resonant tunneling through perovskite double-barriers

The negative differential resistance (NDR) due to resonance tunneling is achieved at room temperature in perovskite double-barrier heterostructures composed of a 10 unit-cell-thick SrTiO3 quantum well sandwiched in two 10 unit-cell-thick LaAlO3 barriers. The NDR occurs at 1.2 V and does not change with voltage cycling. When the paraelectric SrTiO3 quantum well is replaced by a ferroelectric BaTiO3, the onset of the NDR can be modulated by polarization switching in the ultrathin BaTiO3. A polarization pointing to the collector lowers the NDR voltage but a polarization pointing to the emitter increases it. The shift of the NDR voltage is ascribed to reversal of the extra electric field in the quantum well due to the polarization switching. (C) 2014 AIP Publishing LLC.