Quantum-well tunneling anisotropic magnetoresistance above room temperature

Abstract

Quantum-well (QW) devices have been extensively investigated in semiconductor structures. More recently, spin-polarized QWs were integrated into magnetic tunnel junctions (MTJs). In this work, we demonstrate the spin-based control of the quantized states in iron $3d$-band QWs, as observed in experiments and theoretical calculations. We find that the magnetization rotation in the Fe QWs significantly shifts the QW quantization levels, which modulate the resonant-tunneling current in MTJs, resulting in a tunneling anisotropic magnetoresistance (TAMR) effect of QWs. This QW-TAMR effect is sizable compared to other types of TAMR effect, and it is present above the room-temperature. In a QW MTJ of Cr/Fe/MgAl${}_2$O${}_4$/top electrode, where the QW is formed by a mismatch between Cr and Fe in the $d$ band with ${\Delta }_1$ symmetry, a QW-TAMR ratio of up to 5.4 % was observed at 5 K, which persisted to 1.2 % even at 380K. The magnetic control of QW transport can open new applications for spin-coupled optoelectronic devices, ultra-thin sensors, and memories.

References in corpus (18)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Tunneling Anisotropic Magnetoresistance: A spin-valve like tunnel magnetoresistance using a single magnetic layer
• Ballistic conductance of magnetic Co and Ni nanowires with ultrasoft pseudo-potentials
• Tunneling anisotropic magnetoresistance and spin-orbit coupling in Fe/GaAs/Au tunnel junctions
• Tunneling anisotropic magnetoresistance driven by resonant surface states: First-principles calculations of Fe(001) surface
• Tunneling anisotropic magnetoresistance in multilayer-(Co/Pt)/AlOx/Pt structures
• Intrinsic mechanism for anisotropic magnetoresistance and experimental confirmation in Co${}_x$Fe${}_{1-x}$ single-crystal films
• A first-principles study of tunneling magnetoresistance in Fe/MgAl2O4/Fe(001) magnetic tunnel junctions
• Anisotropic magnetoresistance and anisotropic tunneling magnetoresistance due to quantum interference in ferromagnetic metal break junctions
• Long range phase coherencein double barrier magnetic tunnel junctions with large thick metallic quantum well
• Spin-dependent resonant tunneling through quantum-well states in magnetic metallic thin films
• Nonlinear electric field effect on perpendicular magnetic anisotropy in Fe/MgO interfaces
• Large perpendicular magnetic anisotropy in epitaxial Fe/MgAl2O4(001) heterostructures
• Symmetry Dependent Scattering by Minority Interface Resonance States in Single-crystal Magnetic Tunnel Junctions
• Tunneling Anisotropic Magnetoresistance in Co/AlOx/Au Tunnel Junctions
• Artificial control of the bias-voltage dependence of tunnelling anisotropic magnetoresistance using quantization in a single-crystal ferromagnet
• Quantum Lifetime of Two-Dimensional Holes