title: Synaptic Plasticity Selectively Activated by Polarization-Dependent Energy-Efficient Ion Migration in an Ultrathin Ferroelectric Tunnel Junction.
abstract: Selectively activated inorganic synaptic devices, showing a high on/off ratio, ultrasmall dimensions, low power consumption, and short programming time, are required to emulate the functions of high-capacity and energy-efficient reconfigurable human neural systems combining information storage and processing ( Li et al. Sci. Rep. 2014 , 4 , 4096 ). Here, we demonstrate that such a synaptic device is realized using a Ag/PbZr0.52Ti0.48O3(PZT)/La0.8Sr0.2MnO3(LSMO) ferroelectric tunnel junction (FTJ) with ultrathin PZT (thickness of ∼4 nm). Ag ion migration through the very thin FTJ enables a large on/off ratio (107) and low energy consumption (potentiation energy consumption = ∼22 aJ and depression energy consumption = ∼2.5 pJ). In addition, the simple alignment of the downward polarization in PZT selectively activates the synaptic plasticity of the FTJ and the transition from short-term plasticity to long-term potentiation.
authors.affiliation: Division of Quantum Phases & Devices, Department of Physics, Konkuk University , Seoul 143-701, Korea.
authors.forename: Chansoo
authors.initials: C
authors.lastname: Yoon
authors.affiliation: Division of Quantum Phases & Devices, Department of Physics, Konkuk University , Seoul 143-701, Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Quantum Phases & Devices, Department of Physics, Konkuk University , Seoul 143-701, Korea.
authors.forename: Sangik
authors.initials: S
authors.lastname: Lee
authors.affiliation: Division of Quantum Phases & Devices, Department of Physics, Konkuk University , Seoul 143-701, Korea.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Jeon
authors.affiliation: School of Electrical Engineering, Kookmin University , Seoul 136-702, Korea.
authors.forename: Jun Tae
authors.initials: JT
authors.lastname: Jang
authors.affiliation: School of Electrical Engineering, Kookmin University , Seoul 136-702, Korea.
authors.forename: Dae Hwan
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Korea Research Institute of Standards and Science , Daejeon 305-304, Korea.
authors.forename: Young Heon
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Division of Quantum Phases & Devices, Department of Physics, Konkuk University , Seoul 143-701, Korea.
authors.forename: Bae Ho
authors.identifier: 0000-0003-0928-329X
authors.initials: BH
authors.lastname: Park
keywords: Ultrathin ferroelectric film; giant on/off ratio; low energy consumption; selective activation; synaptic device