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Title: Large magnetoresistance from long-range interface coupling in armchair graphene nanoribbon junctions

In recent years, bottom-up synthesis procedures have achieved significant advancements in atomically controlled growth of several-nanometer-long graphene nanoribbons with armchair-shaped edges (AGNRs). This greatly encourages us to explore the potential of such well-defined AGNRs in electronics and spintronics. Here, we propose an AGNR based spin valve architecture that induces a large magnetoresistance up to 900%. We find that, when an AGNR is connected perpendicularly to zigzag-shaped edges, the AGNR allows for long-range extension of the otherwise localized edge state. The huge magnetoresistance is a direct consequence of the coupling of two such extended states from both ends of the AGNR, which forms a perfect transmission channel. By tuning the coupling between these two spin-polarized states with a magnetic field, the channel can be destroyed, leading to an abrupt drop in electron transmission.
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [1] ;  [2]
  1. Department of Physics, Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 2 Science Drive 3, Singapore 117551 (Singapore)
  2. (Singapore)
  3. Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22395542
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COUPLING; ELECTRIC CONTACTS; ELECTRONS; GRAPHENE; INTERFACES; MAGNETIC FIELDS; MAGNETORESISTANCE; NANOSTRUCTURES; SEMICONDUCTOR JUNCTIONS; SPIN; SPIN ORIENTATION; SYNTHESIS; VALVES