Gate-tunable black phosphorus spin valve with nanosecond spin lifetimes

Bibliographic Details
Title: Gate-tunable black phosphorus spin valve with nanosecond spin lifetimes
Authors: Avsar, Ahmet, Tan, Jun You, Kurpas, Marcin, Gmitra, Martin, Watanabe, Kenji, Taniguchi, Takashi, Fabian, Jaroslav, Ozyilmaz, Barbaros
Publication Year: 2017
Collection: Condensed Matter
Subject Terms: Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Other Condensed Matter
More Details: 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.
Document Type: Working Paper
DOI: 10.1038/nphys4141
Access URL: http://arxiv.org/abs/1706.02076
Accession Number: edsarx.1706.02076
Database: arXiv
More Details
DOI:10.1038/nphys4141