Graphene–ferroelectric metadevices for nonvolatile memory and reconfigurable logic-gate operations

Abstract

Memory metamaterials are artificial media that sustain transformed electromagnetic properties without persistent external stimuli. Previous memory metamaterials were realized with phase-change materials, such as vanadium dioxide or chalcogenide glasses, which exhibit memory behaviour with respect to electrically/optically induced thermal stimuli. However, they require a thermally isolated environment for longer retention or strong optical pump for phase-change. Here we demonstrate electrically programmable nonvolatile memory metadevices realised by the hybridization of graphene, a ferroelectric and meta-atoms/meta-molecules, and extend the concept further to establish reconfigurable logic-gate metadevices. For a memory metadevice having a single electrical input, amplitude, phase and even the polarization multi-states were clearly distinguishable with a retention time of over 10 years at room temperature. Furthermore, logic-gate functionalities were demonstrated with reconfigurable logic-gate metadevices having two electrical inputs, with each connected to separate ferroelectric layers that act as the multi-level controller for the doping level of the sandwiched graphene layer.

Prospects of spintronics based on 2D materials

“…Recently, Kim et al demonstrated electrically programmable nonvolatile memory and reconfigurable logic‐gate devices using the hybridization of graphene, a ferroelectric, and meta‐molecules . These metadevices operate at room temperature with superior nonvolatility and very flexible logic function.…”

Graphene Exfoliation at a Ferroelectric Domain Wall Induced by the Piezoelectric Effect: Impact on the Conductance of the Graphene Channel

“…The effects eventually leads to the size-induced phase transition to a paraelectric phase with the film thickness decrease below the critical thickness . At that the critical thickness depends on the gap and/or dead layer thickness in a self-consistent way, and usually does not exceed (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) only, it appeared proportional to both of these values. Actually, the full step width w, defined as the distance between its maximal positive and negative displacement (shown by a horizontal arrow in Fig.2), can be estimated from the expression:…”

“…The consideration of the first of these three effects, performed in this work, are promising for advanced applications of graphene-on-ferroelectric with domain structure in GFETs and related memory elements, various logic devices, as well as for design of high efficient hybrid electrical modulators, rectifiers and transducers of voltage-to-current type [7][8][9][10][11][12][13][14][15][16]21].…”

“…. The two addends in brackets of Eq (8). correspond to the conductance of the bonded (denoted by subscript "B") and separated (denote by subscript "S") sections of the graphene channel, respectively.…”

Nontrivial temperature behavior of the carrier concentration in graphene on ferroelectric substrate with domain walls

“…Kurchak et al [22,23] revealed that adsorbed charges dynamics leads to the hysteresis effect on conductivity in the graphene channel on an organic ferroelectric substrate. Kim et al [24] propose graphene on ferroelectric for nonvolatile memory and reconfigurable logic-gate operations.…”