Expression of Concern: An analytical impedance-based compact model for capturing the resonance wavelength of a nanoshell resonator under dipole approximation

Nanoshells have been utilized in a wide range of applications, from cancer treatment to sensing of chemicals and biological materials. Such applications are based on Surface Plasmon Polariton (SPP) oscillations that nanoshells support, where resonance peaks in the extinction of electromagnetic waves are observed at certain wavelengths that depend on the size of the nanoshell as well as its composite material. In this paper, we develop an impedance model that captures the resonance wavelength of nanoshells allowing for the design of nanoshells to meet specific requirements, depending on the application in which the nanoshell is used. The nanoshell is modeled as a resonator, and the model can accurately and efficiently predict the resonance wavelength of the nanoshell.