Gate-tunable black phosphorus spin valve with nanosecond spin lifetimes
| Autor: | Jun Y. Tan, Takashi Taniguchi, Jaroslav Fabian, Marcin Kurpas, Martin Gmitra, Barbaros Özyilmaz, Kenji Watanabe, Ahmet Avsar |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Electron mobility
Band gap Spin valve General Physics and Astronomy FOS: Physical sciences 02 engineering and technology Electron 01 natural sciences Condensed Matter::Materials Science 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 010306 general physics Spin-½ Physics Condensed matter physics Spintronics Condensed Matter - Mesoscale and Nanoscale Physics business.industry 021001 nanoscience & nanotechnology Condensed Matter - Other Condensed Matter Semiconductor Charge carrier Condensed Matter::Strongly Correlated Electrons 0210 nano-technology business Other Condensed Matter (cond-mat.other) |
| Popis: | Two-dimensional materials offer new opportunities for both fundamental science and technological applications, by exploiting the electron spin. While graphene is very promising for spin communication due to its extraordinary electron mobility, the lack of a band gap restricts its prospects for semiconducting spin devices such as spin diodes and bipolar spin transistors. The recent emergence of 2D semiconductors could help overcome this basic challenge. In this letter we report the first important step towards making 2D semiconductor spin devices. We have fabricated a spin valve based on ultra-thin (5 nm) semiconducting black phosphorus (bP), and established fundamental spin properties of this spin channel material which supports all electrical spin injection, transport, precession and detection up to room temperature (RT). Inserting a few layers of boron nitride between the ferromagnetic electrodes and bP alleviates the notorious conductivity mismatch problem and allows efficient electrical spin injection into an n-type bP. In the non-local spin valve geometry we measure Hanle spin precession and observe spin relaxation times as high as 4 ns, with spin relaxation lengths exceeding 6 um. Our experimental results are in a very good agreement with first-principles calculations and demonstrate that Elliott-Yafet spin relaxation mechanism is dominant. We also demonstrate that spin transport in ultra-thin bP depends strongly on the charge carrier concentration, and can be manipulated by the electric field effect. |
| Databáze: | OpenAIRE |
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