Highly Sensitive Gas and Temperature Sensor Based on Conductance Modulation in Graphene with Multiple Magnetic Barriers

The electronic and transport properties of graphene modulated by magnetic barrier arrays are derived for finite temperature. Prominent conductance gaps, originating from quantum interference effects are found in the periodic array case. When a structural defect is inserted in the array, sharp defect modes of high conductance appear within the conductance gaps. These modes can be shifted by local doping in the defect region resulting into sensing of the chemical molecules that adhere on the graphene sheet. In general it is found that sensitivity is strongly dependent on temperature due to smoothing out of the defect-induced peaks and transport gaps. This temperature dependence, however, offers the added capability for sub-mK temperature sensing resolution, and thus an opportunity towards ultra-sensitive combined electrochemical-calorimetric sensing.