1D ferromagnetic edge contacts to 2D graphene/h-BN heterostructures
Artikel i vetenskaplig tidskrift, 2018

We report the fabrication of one-dimensional (1D) ferromagnetic edge contacts to two-dimensional (2D) graphene/h-BN heterostructures. While aiming to study spin injection/detection with 1D edge contacts, a spurious magnetoresistance signal was observed, which is found to originate from the local Hall effect in graphene due to fringe fields from ferromagnetic edge contacts and in the presence of charge current spreading in the nonlocal measurement configuration. Such behavior has been confirmed by the absence of a Hanle signal and gate-dependent magnetoresistance measurements that reveal a change in sign of the signal for the electron-and hole-doped regimes, which is in contrast to the expected behavior of the spin signal. Calculations show that the contact-induced fringe fields are typically on the order of hundreds of mT, but can be reduced below 100 mT with careful optimization of the contact geometry. There may be an additional contribution from magnetoresistance effects due to tunneling anisotropy in the contacts, which needs further investigation. These studies are useful for optimization of spin injection and detection in 2D material heterostructures through 1D edge contacts.

spintronics

1D edge contact

spin-valve

CVD

graphene

stray field

h-BN

Författare

Bogdan Karpiak

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

André Dankert

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

A. W. Cummings

S. R. Power

Stefan Roche

Saroj Prasad Dash

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

2D Materials

2053-1583 (eISSN)

Vol. 5 1 014001-

Graphene-Based Revolutions in ICT And Beyond (Graphene Flagship)

Europeiska kommissionen (FP7), 2013-10-01 -- 2016-03-31.

Styrkeområden

Nanovetenskap och nanoteknik

Ämneskategorier

Atom- och molekylfysik och optik

Den kondenserade materiens fysik

DOI

10.1088/2053-1583/aa8d2b