Gap state charge induced spin-dependent negative differential resistance in tunnel junctions

Abstract

We propose and demonstrate through first-principles calculation a new spin-dependent negative differential resistance (NDR) mechanism in magnetic tunnel junctions (MTJ) with cubic cation disordered crystals (CCDC) AlO${}_x$ or Mg${}_{1-x}$Al${}_x$O as barrier materials. The CCDC is a class of insulators whose band gap can be changed by cation doping. The gap becomes arched in an ultrathin layer due to the space charge formed from metal-induced gap states. With an appropriate combination of an arched gap and a bias voltage, NDR can be produced in either spin channel. This mechanism is applicable to 2D and 3D ultrathin junctions with a sufficiently small band gap that forms a large space charge. It provides a new way of controlling the spin-dependent transport in spintronic devices by an electric field. A generalized Simmons formula for tunneling current through junction with an arched gap is derived to show the general conditions under which ultrathin junctions may exhibit NDR.

arXiv comment6 pages, 7 figures

References in corpus (14)

• Energy Band Gap Engineering of Graphene Nanoribbons
• Physics of thin-film ferroelectric oxides
• Biased bilayer graphene: semiconductor with a gap tunable by electric field effect
• Room Temperature All Semiconducting sub-10nm Graphene Nanoribbon Field-Effect Transistors
• Gate-tunable Memristive Phenonmena Mediated by Grain Boundaries in Single Layer MoS2
• Colossal electroresistance in metal/ferroelectric/semiconductor tunnel diodes for resistive switching memories
• Electronic transport and quantum Hall effect in bipolar graphene p-n-p junction
• Resonant Electron Transport in Single-Molecule Junctions: Vibrational Excitation, Rectification, Negative Differential Resistance and Local Cooling
• Structural phase transitions and fundamental band gaps of Mg(x)Zn(1-x)O alloys from first principles
• Spin-dependent resonant tunneling through quantum-well states in magnetic metallic thin films
• Tunable Negative Differential Resistance controlled by Spin Blockade in Single Electron Transistors
• Visualizing Atomic-Scale Negative Differential Resistance in Bilayer Graphene
• Negative differential resistance in graphene-based ballistic field effect transistor with oblique top gate
• Negative differential conductance and magnetoresistance oscillations due to spin accumulation in ferromagnetic double-island devices

Cited by in corpus (1)

• First-Principles Theory for Schottky Barrier Physics