2016/04/01 by Jun Jiang, X.-G. Zhang, X. -G. Zhang +1 · 3 citations
Physics and Astronomy · #Air gap (plumbing) #Band gap #Charge (physics) #Differential (mechanical device) #Insulator (electricity) #Magnetic properties of thin films #Quantum and electron transport phenomena #Quantum tunnelling #Space charge #Topological Materials and Phenomena #Tunnel junction #cond-mat.mtrl-sci
paper · pdf · doi:10.1209/0295-5075/114/17005
published in Europhysics Letters (EPL) 114(1), 17005 (Institute of Physics) · 6 pages, 7 figures
openalex publication_date 2016/04/01 · arxiv created 2016/04/05 · arxiv updated 2016/05/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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.