Two-band model of spin-polarized tunneling incorporating discrete charging energy

2003 ◽  
Vol 93 (10) ◽  
pp. 8056-8058 ◽  
Author(s):  
X. Wang ◽  
M. B. A. Jalil
Keyword(s):  
Band Model ◽  
Spin Polarized ◽  
Charging Energy ◽  
Two Band Model ◽  
Spin Polarized Tunneling

A two-band model of spin-polarized transport in Fe/Cr/MgO/Fe magnetic tunnel junctions

2010 ◽  
Vol 107 (9) ◽  
pp. 09C720 ◽  
Author(s):  
A. Vedyaev ◽  
N. Ryzhanova ◽  
N. Strelkov ◽  
M. Chshiev ◽  
B. Dieny
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Band Model ◽  
Spin Polarized ◽  
Polarized Transport ◽  
Spin Polarized Transport ◽  
Two Band Model

scholarly journals Manipulation of hot carrier cooling dynamics in two-dimensional Dion–Jacobson hybrid perovskites via Rashba band splitting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jun Yin ◽  
Rounak Naphade ◽  
Partha Maity ◽  
Luis Gutiérrez-Arzaluz ◽  
Dhaifallah Almalawi ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Phonon Scattering ◽  
Transient Absorption Spectroscopy ◽  
Band Model ◽  
Two Dimensional ◽  
Spintronic Devices ◽  
Hot Carrier ◽  
Band Splitting ◽  
Perovskite Materials ◽  
Spin Polarized

AbstractHot-carrier cooling processes of perovskite materials are typically described by a single parabolic band model that includes the effects of carrier-phonon scattering, hot phonon bottleneck, and Auger heating. However, little is known (if anything) about the cooling processes in which the spin-degenerate parabolic band splits into two spin-polarized bands, i.e., the Rashba band splitting effect. Here, we investigated the hot-carrier cooling processes for two slightly different compositions of two-dimensional Dion–Jacobson hybrid perovskites, namely, (3AMP)PbI4 and (4AMP)PbI4 (3AMP = 3-(aminomethyl)piperidinium; 4AMP = 4-(aminomethyl)piperidinium), using a combination of ultrafast transient absorption spectroscopy and first-principles calculations. In (4AMP)PbI4, upon Rashba band splitting, the spin-dependent scattering of hot electrons is responsible for accelerating hot-carrier cooling at longer delays. Importantly, the hot-carrier cooling of (4AMP)PbI4 can be extended by manipulating the spin state of the hot carriers. Our findings suggest a new approach for prolonging hot-carrier cooling in hybrid perovskites, which is conducive to further improving the performance of hot-carrier-based optoelectronic and spintronic devices.

Spin-polarized tunneling through a ferromagnetic insulator

2009 ◽  
Vol 105 (7) ◽  
pp. 07C919
Author(s):  
M. Kok ◽  
J. N. Beukers ◽  
A. Brinkman
Keyword(s):  
Spin Polarized ◽  
Spin Polarized Tunneling

IONIZATION ENERGY AND IMPURITY BAND CONDUCTION OF SHALLOW DONORS IN n-GALLIUM ARSENIDE

1967 ◽  
Vol 45 (1) ◽  
pp. 119-126 ◽  
Author(s):  
J. Basinski ◽  
R. Olivier
Keyword(s):  
Ionization Energy ◽  
Impurity Band ◽  
Shallow Donor ◽  
Band Model ◽  
A Value ◽  
Transition Concentration ◽  
Temperature Electron ◽  
Two Band Model ◽  
Band Conduction ◽  
Made In

Hall effect and resistivity measurements have been made in the temperature range 4.2–360 °K on several samples of n-type GaAs grown under oxygen atmosphere and without any other intentional dopings. The principal shallow donor in this material is considered to be Si. All samples exhibited impurity-band conduction at low temperature. Electron concentrations in the conduction band were calculated, using a two-band model, and then fitted to the usual equation expressing charge neutrality. A value of 2.3 × 10−3 eV was obtained for the ionization energy of the donors, for donor concentration ranging from 5 × 1015 cm−3 to 2 × 1016 cm−3. The conduction in the impurity band was of the hopping type for these concentrations. A value of 3.5 × 1016 cm−3 was obtained for the critical transition concentration of the impurity-band conduction to the metallic type.

ENERGY BAND OVERLAPPING IN HIGH-Tc SUPERCONDUCTORS

1996 ◽  
Vol 10 (30) ◽  
pp. 1483-1490 ◽  
Author(s):  
M. MORENO ◽  
R. M. MÉNDEZ-MORENO ◽  
M. A. ORTIZ ◽  
S. OROZCO
Keyword(s):  
Weak Coupling ◽  
Cuprate Superconductors ◽  
Weak Coupling Limit ◽  
Band Model ◽  
Coupling Constant ◽  
High Tc Superconductors ◽  
Energy Bands ◽  
Effective Coupling ◽  
High Tc ◽  
Two Band Model

Multi-band superconductors are analyzed and the relevance of overlapping energy bands to the high-T c of these materials is studied. Within the BCS framework, a two band model with generalized Fermi surface topologies is developed. Values of the overlapped occupancy parameters for typical cuprate superconductors are obtained as a function of the ratio R and the effective coupling constant, λ, in the weak-coupling limit. The overlap scale is of the order or lower than the cutoff (Debye) energy. The typical behavior of the isotope effect is obtained. As these superconductors have transition temperatures above the phonon barrier, the results of this approach are important to the generic understanding of the high-T c superconducting mechanism.

Thermoelectric Power of the Liquid Sn—Te Alloy

1982 ◽  
Vol 37 (10) ◽  
pp. 1127-1131 ◽  
Author(s):  
D. H. Kurlat ◽  
M. Rosen
Keyword(s):  
Thermoelectric Power ◽  
Hard Sphere ◽  
Stoichiometric Composition ◽  
Band Model ◽  
Liquid Alloys ◽  
Sphere Approximation ◽  
The Difference ◽  
Predicted Values ◽  
Experimental Values ◽  
Two Band Model

The Seebeck coefficient (S) of Sni1-x- Tex liquid alloys was measured as a function of concentration and temperature. For 0 ≦ x <0.45 the behaviour is metallic; S values are small and negative, rising linearly with temperature. The predicted values of Ziman's theory when using the hard sphere approximation disagree with the experimental ones. The change in sign occurs for 0.45. For x = 0.5 (stoichiometric composition) the thermoelectric power decreases linearly with temperature. This fact is explained assuming a two-band model. For x ≧ 0.6 the liquid alloy becomes more semiconducting and presents a maximum in the isotherms of S for x = 0.65. For the excess tellurium concentration range we have calculated the difference EF - EV and γ/kB, assuming a S(1/T) law. The experimental values are compared with those of Dancy and Glazov.

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