A graphene quantum dot with a single electron transistor as an integrated charge sensor

摘要

A quantum dot u0002QDu0003 with an integrated charge sensor is becoming a common architecture for a spinnor charge based solid state qubit. To implement such a structure in graphene, we have fabricated antwin-dot structure in which the larger dot serves as a single electron transistor u0002SETu0003 to read out thencharge state of the nearby gate controlled small QD. A high SET sensitivity of 10−3ne/u0004Hz allowednus to probe Coulomb charging as well as excited state spectra of the QD, even in the regime wherenthe current through the QD is too small to be measured by conventional transport means. © 2010nAmerican Institute of Physics. u0005doi:10.1063/1.3533021