Independently Tunable Multichannel Filters Based on Graphene Superlattices with Fractal Potential Patterns

An independently tunable multichannel filter based on graphene superlattices with fractal potentials is theoretically studied. It is found that such fractal structures with a defect layer possess an unusual tunneling state occurring inside the forbidden gap, and the defect modes can be modulated by changing the width of the defect layer. The facts that the wave functions of defect states do not overlap and their bases are orthogonal lead to the result of the independency among the defect modes. The modulation of energy, energy interval and number of the defect modes may lead to potential applications in graphene-based electronic devices.