Abstract:The tunnel magnetoresistance (TMR) in the magnetic tunnel junction (MTJ) with embedded nanoparticles (NPs) was calculated in range of the quantum-ballistic model. The simulation was performed for electron tunneling through the insulating layer with embedded magnetic and non-magnetic NPs within the approach of the double barrier subsystem connected in parallel to the single barrier one. This model can be applied for both MTJs with in-plane magnetization and perpendicular one. We also calculated the in-plane com… Show more
“…Recently, it was theoretically shown that quantized conductance regime is a main reason of the anomalous TMR (suppression or resonant peak-like TMR behaviors) in MTJs with embedded nanoparticles. 1,2 The observed TMR effects are similar to the giant magnetoresistance effects in point-like nano-contacts. 10,16 The consideration of the system in terms of finite temperature T depends on how corresponding energy…”
Section: Resonant Tmr Peaks In Npmtjsupporting
confidence: 53%
“…In this paper, we specified temperature-related effects of the TMR behavior in magnetic tunnel junction with embedded nanoparticles (npMTJ) in range of developed quantum-ballistic approach. 1,2 It is important to note that widely used consecutive and related Coulomb blockade models in literature for similar systems cannot achieve the limit of the ballistic approach due to its basic definition. For example, exploring the tunnel magnetoresistance (TMR) anomalies in magnetic tunnel junctions (MTJs) with embedded nanoparticles (NPs) 3 in range of the Kondo-assisted cotunneling and sequential tunneling regimes of the conductance, but direct tunneling was omitted.…”
Temperature dependence of the tunnel magnetoresistance (TMR) was calculated in range of the quantum-ballistic model in the magnetic tunnel junction (MTJ) with embedded nanoparticles (NPs). The electron tunnel transport through NP was simulated in range of double barrier approach, which was integrated into the model of the magnetic point-like contact. The resonant TMR conditions and temperature impact were explored in detail. Moreover, the possible reasons of the temperature induced resonant conditions were discussed in the range of the lead-tunneling cell (TC)-lead model near Kondo temperature. We also found that redistribution of the voltage drop becomes crucial in this model. Furthermore, the direct tunneling plays the dominant role and cannot be omitted in the quantum systems with the total tunneling thickness up to 5-6 nm. Hence, Coulomb blockade model cannot explain Kondoinduced TMR anomalies in nanometer-sized tunnel junctions.
“…Recently, it was theoretically shown that quantized conductance regime is a main reason of the anomalous TMR (suppression or resonant peak-like TMR behaviors) in MTJs with embedded nanoparticles. 1,2 The observed TMR effects are similar to the giant magnetoresistance effects in point-like nano-contacts. 10,16 The consideration of the system in terms of finite temperature T depends on how corresponding energy…”
Section: Resonant Tmr Peaks In Npmtjsupporting
confidence: 53%
“…In this paper, we specified temperature-related effects of the TMR behavior in magnetic tunnel junction with embedded nanoparticles (npMTJ) in range of developed quantum-ballistic approach. 1,2 It is important to note that widely used consecutive and related Coulomb blockade models in literature for similar systems cannot achieve the limit of the ballistic approach due to its basic definition. For example, exploring the tunnel magnetoresistance (TMR) anomalies in magnetic tunnel junctions (MTJs) with embedded nanoparticles (NPs) 3 in range of the Kondo-assisted cotunneling and sequential tunneling regimes of the conductance, but direct tunneling was omitted.…”
Temperature dependence of the tunnel magnetoresistance (TMR) was calculated in range of the quantum-ballistic model in the magnetic tunnel junction (MTJ) with embedded nanoparticles (NPs). The electron tunnel transport through NP was simulated in range of double barrier approach, which was integrated into the model of the magnetic point-like contact. The resonant TMR conditions and temperature impact were explored in detail. Moreover, the possible reasons of the temperature induced resonant conditions were discussed in the range of the lead-tunneling cell (TC)-lead model near Kondo temperature. We also found that redistribution of the voltage drop becomes crucial in this model. Furthermore, the direct tunneling plays the dominant role and cannot be omitted in the quantum systems with the total tunneling thickness up to 5-6 nm. Hence, Coulomb blockade model cannot explain Kondoinduced TMR anomalies in nanometer-sized tunnel junctions.
“…2]), where the deposition of the middle layer is responsible for the NPs fraction formation. We assume that the peak-like TMR voltage dependence can be a result of the resonance tunneling and the beginning of the conductance quantized regime [9].…”
Section: A Tmr-v Anomalies At Zero-voltage Regionmentioning
In this paper, we attempt the theoretical modeling of the magnetic tunnel junctions with embedded magnetic and nonmagnetic nanoparticles (NPs). A few abnormal tunnel magnetoresistance (TMR) effects, observed in related experiments, can be easily simulated within our model: we found, that the suppressed TMR magnitudes and the TMR sign-reversing effect at small voltages are related to the electron momentum states of the NP located inside the insulating layer. All these TMR behaviors can be explained within the tunneling model, where NP is simulated as a quantum well (QW). The coherent (direct) double barrier tunneling is dominating over the single barrier one. The origin of the TMR suppression is the quantized angle transparency for spin polarized electrons being in one of the lowest QW states. The phenomenon was classified as the quantized conductance regime due to restricted geometry.
“…The fraction is defined as a set of TCs with the same size of NPs. The ballistic tunneling was considered as a basic transport approach, and the current for each TC was defined as follows 18 , 19 : Figure 1 Schematic model of the NP-MTJ. Blue and red arrows show parallel (P) and anti-parallel (AP) magnetic configurations, respectively.…”
The problem of the ballistic electron tunneling is considered in magnetic tunnel junction with embedded non-magnetic nanoparticles (NP-MTJ), which creates additional conducting middle layer. The strong temperature impact was found in the system with averaged NP diameter d
av < 1.8 nm. Temperature simulation is consistent with experimental observations showing the transition between dip and classical dome-like tunneling magnetoresistance (TMR) voltage behaviors. The low temperature approach also predicts step-like TMR and quantized in-plane spin transfer torque (STT) effects. The robust asymmetric STT respond is found due to voltage sign inversion in NP-MTJs with barrier asymmetry. Furthermore, it is shown how size distribution of NPs as well as quantization rules modify the spin-current filtering properties of the nanoparticles in ballistic regime. Different quantization rules for the transverse component of the wave vector are considered to overpass the dimensional threshold (d
av ≈ 1.8 nm) between quantum well and bulk-assisted states of the middle layer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
