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Significant change of spin transport property in Cu/Nb bilayer due to superconducting transition.

Ohnishi K, Ono Y, Nomura T, Kimura T - Sci Rep (2014)

Bottom Line: To observe such SC spin transports, the suppression of the extrinsic effects originating from the heating and Oersted field due to the electric current is a crucial role.Pure spin current without accompanying the charge current is known as a powerful mean for preventing such extrinsic effects.By using this ideal platform, we found that the spin absorption is strongly suppressed by the SC transition of Nb.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan [2] Research Center for Quantum Nano-Spin Sciences, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.

ABSTRACT
The combination between the spin-dependent and super-conducting (SC) transports is expected to provide intriguing properties such as crossed Andreev reflection and spin-triplet superconductivity. This may be able to open a new avenue in the field of spintronics, namely superconducting spintronics because a superconductor itself has great potential for future nanoelectronic applications. To observe such SC spin transports, the suppression of the extrinsic effects originating from the heating and Oersted field due to the electric current is a crucial role. Pure spin current without accompanying the charge current is known as a powerful mean for preventing such extrinsic effects. However, non-negligible heat flow is found to exist even in a conventional pure spin current device based on laterally-configured spin valve because of the heating around the spin injector. Here, we develop a nanopillar-based lateral spin valve, which significantly reduces the heat generation, on a superconducting Nb film. By using this ideal platform, we found that the spin absorption is strongly suppressed by the SC transition of Nb. This demonstration is the clear evidence that the super-conducting Nb is an insulator for the pure spin current.

No MeSH data available.


Related in: MedlinePlus

Scanning electron microscope image together with a schematic illustration of the prepared nano-pillar-based lateral spin valve.Two Py nanopillars are placed on the Cu/Nb bilayer film and are connected to the top Cu electrodes.
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f1: Scanning electron microscope image together with a schematic illustration of the prepared nano-pillar-based lateral spin valve.Two Py nanopillars are placed on the Cu/Nb bilayer film and are connected to the top Cu electrodes.

Mentions: Figure 1 shows a scanning electron microscope image of the fabricated device together with the schematic illustration of the device. First, we have prepared the Py/Cu/Nb trilayer film by using a high vacuum sputtering and evaporation system with the base pressure less than 2 × 10−5 Pa. Here, Nb and Py are 45-nm thick and 30-nm thick, respectively, and were deposited by the magnetron sputterings. The Cu spacer whose thickness is 100 nm was deposited by the Joule evaporation. Then, the trilayer film was patterned into the nanopillar structure by using electron-beam lithography and Ar ion milling. The detail of the fabrication procedure is described in our previous paper31. The lateral dimensions for two ferromagnetic nanopillars are 270 × 220 nm2 and 340 × 240 nm2, and the center-center distance between two ferromagnetic nanopillars is approximately 500 nm. Since the trilayer was prepared by in-situ multi-layered film grown system, the interfaces between each metal have ideal conditions.


Significant change of spin transport property in Cu/Nb bilayer due to superconducting transition.

Ohnishi K, Ono Y, Nomura T, Kimura T - Sci Rep (2014)

Scanning electron microscope image together with a schematic illustration of the prepared nano-pillar-based lateral spin valve.Two Py nanopillars are placed on the Cu/Nb bilayer film and are connected to the top Cu electrodes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4151101&req=5

f1: Scanning electron microscope image together with a schematic illustration of the prepared nano-pillar-based lateral spin valve.Two Py nanopillars are placed on the Cu/Nb bilayer film and are connected to the top Cu electrodes.
Mentions: Figure 1 shows a scanning electron microscope image of the fabricated device together with the schematic illustration of the device. First, we have prepared the Py/Cu/Nb trilayer film by using a high vacuum sputtering and evaporation system with the base pressure less than 2 × 10−5 Pa. Here, Nb and Py are 45-nm thick and 30-nm thick, respectively, and were deposited by the magnetron sputterings. The Cu spacer whose thickness is 100 nm was deposited by the Joule evaporation. Then, the trilayer film was patterned into the nanopillar structure by using electron-beam lithography and Ar ion milling. The detail of the fabrication procedure is described in our previous paper31. The lateral dimensions for two ferromagnetic nanopillars are 270 × 220 nm2 and 340 × 240 nm2, and the center-center distance between two ferromagnetic nanopillars is approximately 500 nm. Since the trilayer was prepared by in-situ multi-layered film grown system, the interfaces between each metal have ideal conditions.

Bottom Line: To observe such SC spin transports, the suppression of the extrinsic effects originating from the heating and Oersted field due to the electric current is a crucial role.Pure spin current without accompanying the charge current is known as a powerful mean for preventing such extrinsic effects.By using this ideal platform, we found that the spin absorption is strongly suppressed by the SC transition of Nb.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan [2] Research Center for Quantum Nano-Spin Sciences, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.

ABSTRACT
The combination between the spin-dependent and super-conducting (SC) transports is expected to provide intriguing properties such as crossed Andreev reflection and spin-triplet superconductivity. This may be able to open a new avenue in the field of spintronics, namely superconducting spintronics because a superconductor itself has great potential for future nanoelectronic applications. To observe such SC spin transports, the suppression of the extrinsic effects originating from the heating and Oersted field due to the electric current is a crucial role. Pure spin current without accompanying the charge current is known as a powerful mean for preventing such extrinsic effects. However, non-negligible heat flow is found to exist even in a conventional pure spin current device based on laterally-configured spin valve because of the heating around the spin injector. Here, we develop a nanopillar-based lateral spin valve, which significantly reduces the heat generation, on a superconducting Nb film. By using this ideal platform, we found that the spin absorption is strongly suppressed by the SC transition of Nb. This demonstration is the clear evidence that the super-conducting Nb is an insulator for the pure spin current.

No MeSH data available.


Related in: MedlinePlus