Boosting room temperature tunnel magnetoresistance in hybrid magnetic tunnel junctions under electric bias

Spin-resolved electron symmetry filtering is a key mechanism behind gianttunneling magnetoresistance (TMR) in Fe/MgO/Fe and similar magnetictunnel junctions (MTJs), providing room temperature functionality in spinelectronics. However, the electron symmetry filtering breaks down underapplied bias, dr...

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Detalles Bibliográficos
Autores: González-Ruano Iriarte, César, Tiusan, Coriolan, Hehn, Michel, Aliev Kazanski, Farkhad
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/713967
Acceso en línea:http://hdl.handle.net/10486/713967
https://dx.doi.org/10.1002/aelm.202100805
Access Level:acceso abierto
Palabra clave:Bias dependence
Interfacial states
Spin-orbit coupling
Tunneling magnertoresistance
Física
Descripción
Sumario:Spin-resolved electron symmetry filtering is a key mechanism behind gianttunneling magnetoresistance (TMR) in Fe/MgO/Fe and similar magnetictunnel junctions (MTJs), providing room temperature functionality in spinelectronics. However, the electron symmetry filtering breaks down underapplied bias, dramatically reducing the TMR above 0.5 V. This strongly ham-pers the application range of MTJs. To circumvent the problem, resonant tun-neling through quantum well states in thin layers has been used so far. Thismechanism, however, is mainly effective at low temperatures. Here, a funda-mentally different approach is demonstrated, providing a strong TMR boostunder applied bias in V/MgO/Fe/MgO/Fe/Co hybrids. This pathway uses spinorbit coupling (SOC) controlled interfacial states in vanadium, which contraryto the V(001) bulk states are allowed to tunnel to Fe(001) at low biases. Theexperimentally observed strong increase of TMR with bias is modeled usingtwo nonlinear resistances in series, with the low bias conductance of the first(V/MgO/Fe) element being boosted by the SOC-controlled interfacial states,while the conductance of the second (Fe/MgO/Fe) junctions are controlled bythe relative alignment of the ferromagnetic layers. These results pave a way tounexplored and fundamentally different spintronic device schemes, with tun-neling magnetoresistance uplifted under applied electric bias