Strontium Oxide Tunnel Barriers for High Quality Spin Transport and Large Spin Accumulation in Graphene

Simranjeet Singh, Jyoti Katoch, Tiancong Zhu, Ryan J. Wu, Adam S. Ahmed, Walid Amamou, Dongying Wang, K. Andre Mkhoyan, Roland K. Kawakami

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

The quality of the tunnel barrier at the ferromagnet/graphene interface plays a pivotal role in graphene spin valves by circumventing the impedance mismatch problem, decreasing interfacial spin dephasing mechanisms and decreasing spin absorption back into the ferromagnet. It is thus crucial to integrate superior tunnel barriers to enhance spin transport and spin accumulation in graphene. Here, we employ a novel tunnel barrier, strontium oxide (SrO), onto graphene to realize high quality spin transport as evidenced by room-temperature spin relaxation times exceeding a nanosecond in graphene on silicon dioxide substrates. Furthermore, the smooth and pinhole-free SrO tunnel barrier grown by molecular beam epitaxy (MBE), which can withstand large charge injection current densities, allows us to experimentally realize large spin accumulation in graphene at room temperature. This work puts graphene on the path to achieve efficient manipulation of nanomagnet magnetization using spin currents in graphene for logic and memory applications.

Original languageEnglish (US)
Pages (from-to)7578-7585
Number of pages8
JournalNano letters
Volume17
Issue number12
DOIs
StatePublished - Dec 13 2017

Bibliographical note

Funding Information:
Authors acknowledge the financial support from C-SPIN, one of the six SRC STARnet Centers, sponsored by MARCO and DARPA. S.S. J.K., T.Z., A.A., W.A., D.W., and R.K.K. also acknowledge support from ONR (No. N00014-14-1-0350) and partial support from the Center for Emergent Materials: an NSF MRSEC under award number DMR-1420451.

Funding Information:
Authors acknowledge the financial support from C-SPIN, one of the six SRC STARnet Centers, sponsored by MARCO and DARPA. S.S., J.K., T.Z., A.A., W.A., D.W., and R.K.K. also acknowledge support from ONR (No. N00014-14-1-0350) and partial support from the Center for Emergent Materials: an NSF MRSEC under award number DMR-1420451. STEM analysis was performed in the Characterization Facility of the University of Minnesota, which receives partial support from NSF through the MRSEC program.

Keywords

  • Graphene spintronics
  • lateral spin valves
  • molecular beam epitaxy
  • spin current and spin accumulation
  • transmission electron microscopy
  • tunnel barrier

How much support was provided by MRSEC?

  • Shared

PubMed: MeSH publication types

  • Journal Article
  • Research Support, Non-U.S. Gov't

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