Investigating Local Moments in Graphene in the Low Temperature Limit

Speaker: Dr. Silvia Luescher Folk
Date & Time: Tuesday June 27, 2017 @ 11:00 am - 12:00 pm
Location: AMPEL 311
Local Contact: Jeff Young, George Sawatzky, Doug Bonn
Intended Audience:

Graphene has been touted as a promising material for spintronics, due to its low intrinsic spin-orbit and hyperfine interactions.  Over the past decade, however, it has become clear that conduction electron spins in most forms of graphene interact strongly with local magnetic moments.  Unfortunately for spintronics applications, these interactions lead to rapid spin relaxation and dephasing.  Well below 1Kelvin, however, spin-flip rates due to the local moments are strongly suppressed, and non-trivial resistance signatures arise.  This talk explores the low temperature state of local moments in graphene.  We prepare devices in which we can tune density of local moments, then measure their magnetoresistance at ultra-low temperatures.  Signatures of Kondo screening and possibly RKKY coupling are observed, as well as others for which a proper theoretical explanation is still lacking.