Peltier Effect in Sub-micron-Size Metallic Junctions

Abstract

A'procedure is described for analysing the fine structure of intermediate structure resonances in which the matrix elements connecting the special state with the ordinary states are extracted directly. The procedure was tested numerically, and found to be satisfactory for cases in which background contributions to the widths are small. The method is applied to several narrow subthreshold fission resonances. NUCLEAR REACTIONS Analysis of intermediate structure fine structure;Np(n, f), 238pu(n, f), w ( n , f); deduced spreading widths of subthreshold fission I resonances. 23'? Permanent address: AERE, Harwell, England.

Thermoelectric effects in magnetic nanostructures

“…5͒ displays similar effect but with smaller amplitudes. For the strongly thermalized electron case, the MPE caused by interface scattering, R 0 ͓I p ͑ ͒ − I p ͑0͔͒, is on the order of 1-10 mV, which is smaller than the experimental values 18,19 R 0 I p Ϸ 20-40 mV. For a typical current density of 10 8 A / cm 2 , we find a maximum temperature drop ⌬T N ͑ ͒Ϸ0.15 K which is also too small to explain experiments.…”

“…For structure elements such as interfaces which are not overly complicated, r mn ͑⑀͒ can be calculated from microscopic, first-principles calculations. [17][18][19][20][21][22][23][24][25][26][27][28][29][30] Thermoelectric effects arise from the energy dependence of G͑⑀͒. The circuit theory approach requires that scattering in the resistive elements is elastic.…”

“…In the magnetic nanopillars considered by Fukushima et al 18,19 the magnetic or normal leads that connect the central spacer to the wide external reservoirs are so long that the bulk scattering is important: a 100-nm-long cobalt wire has a resistance Co L Ӎ 6 f ⍀m 2 at room temperature, which is larger than the interface resistance R Co͉Cu Ϸ 0.25 f ⍀m 2 ͑see Table I͒. The effective thermopower S L Ϸ S Co Ӎ −31 V / K from the bulk scattering is also larger than the interface thermopower S Co͉Cu Ϸ −6 V / K. The interface contribution to the total thermopower would become more important for high-resistance interfaces, such as tunneling barriers or point contacts, or structures with thinner layers.…”

“…The sample cross sections were used as fitting parameters that appeared to be too small compared to the actual sample sizes. 18,19 This discrepancy was attributed to the neglect of interface scattering. Katayama-Yoshida et al 21 interpreted the perceived enhancement of the cooling power as a contribution from an adiabatic spin-entropy expansion term ͑k B / e͒ln 2.…”

Theory of thermal spin-charge coupling in electronic systems

“…18,19 Although the theory of thermoelectricity has long been known, 20,21 only experimental improvements over the past few years have made its application in the context of generating and transporting spin appear possible. [22][23][24][25][26] At the heart of spin caloritronics is the spin Seebeck effect (see Fig. 1).…”