Enhanced spin injection efficiency and extended spin lifetimes in graphene spin valves

被引：2

作者：

Han, Wei ^{[1
]}

Chen, J. R. ^{[1
]}

McCreary, K. M. ^{[1
]}

Wen, H. ^{[1
]}

Kawakami, R. K. ^{[1
]}

机构：

[1] Univ Calif Riverside, Dept Phys & Astron, Riverside, CA 92521 USA

来源：

SPINTRONICS IV | 2011年 / 8100卷

关键词：

Graphene; spin injection; spin lifetimes; spin relaxation; PRECESSION; TRANSPORT; METAL;

D O I：

10.1117/12.901199

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

Enhanced spin injection efficiency and extended spin lifetimes are achieved in graphene spin valves. Spin injection efficiency is enhanced via tunneling spin injection into graphene through an MgO barrier. A large nonlocal magetoresistance of 130 Omega is observed for a single layer graphene (SLG) spin valve at room temperature (RT) with spin injection efficiency of similar to 26-30%. Extended spin lifetimes are observed using tunneling contact to suppress the contact induced spin relaxation. In SLG, spin lifetime as long as 771 ps is observed at RT. In bilayer graphene (BLG), we observe the spin lifetime of 6.2 ns at 20 K, which is the longest value reported in any graphene spin valve. Furthermore, contrasting spin relaxation behaviors are observed in SLG and BLG, which suggests that Elliot-Yafet spin relaxation dominates in SLG at low temperatures, while Dyakonov-Perel spin relaxation dominates in BLG at low temperatures.

引用

页数：8

共 42 条

[21] INTERFACIAL CHARGE-SPIN COUPLING - INJECTION AND DETECTION OF SPIN MAGNETIZATION IN METALS
JOHNSON, M
SILSBEE, RH
[J]. PHYSICAL REVIEW LETTERS, 1985, 55 (17) : 1790 - 1793
[22] Linear scaling between momentum and spin scattering in graphene
Jozsa, C.
Maassen, T.
Popinciuc, M.
Zomer, P. J.
Veligura, A.
Jonkman, H. T.
van Wees, B. J.
[J]. PHYSICAL REVIEW B, 2009, 80 (24):
[23] Electronic spin drift in graphene field-effect transistors
Jozsa, C.
Popinciuc, M.
Tombros, N.
Jonkman, H. T.
van Wees, B. J.
[J]. PHYSICAL REVIEW LETTERS, 2008, 100 (23)
[24] Comparison between charge and spin transport in few-layer graphene
Maassen, T.
Dejene, F. K.
Guimaraes, M. H. D.
Jozsa, C.
van Wees, B. J.
[J]. PHYSICAL REVIEW B, 2011, 83 (11):
[25] Micrometer-Scale Ballistic Transport in Encapsulated Graphene at Room Temperature
Mayorov, Alexander S.
Gorbachev, Roman V.
Morozov, Sergey V.
Britnell, Liam
Jalil, Rashid
Ponomarenko, Leonid A.
Blake, Peter
Novoselov, Kostya S.
Watanabe, Kenji
Taniguchi, Takashi
Geim, A. K.
[J]. NANO LETTERS, 2011, 11 (06) : 2396 - 2399
[26] Meier F., 1984, OPTICAL ORIENTATION, V8
[27] SPIN-POLARIZED ELECTRON-TUNNELING
MESERVEY, R
TEDROW, PM
[J]. PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 1994, 238 (04): : 173 - 243
[28] Spin transport through multilayer graphene
Nishioka, Masaya
Goldman, A. M.
[J]. APPLIED PHYSICS LETTERS, 2007, 90 (25)
[29] Two-dimensional gas of massless Dirac fermions in graphene
Novoselov, KS
Geim, AK
Morozov, SV
Jiang, D
Katsnelson, MI
Grigorieva, IV
Dubonos, SV
Firsov, AA
[J]. NATURE, 2005, 438 (7065) : 197 - 200
[30] Spin injection into a graphene thin film at room temperature
Ohishi, Megumi
Shiraishi, Masashi
Nouchi, Ryo
Nozaki, Takayuki
Shinjo, Teruya
Suzuki, Yoshishige
[J]. JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 2007, 46 (25-28): : L605 - L607

← 1 2 3 4 5 →