Signature of a double quantum-dot structure in the I− V characteristics of a complex system

We demonstrate that by carefully analyzing the temperature dependent characteristics of the I−V measurements for a given complex system, it is possible to determine whether it is composed of a single, double, or multiple quantum-dot structure. Our approach is based on the orthodox theory for a double-dot case and is capable of simulating I−V characteristics of systems with any resistance and capacitance values and for temperatures corresponding to thermal energies larger than the dot level spacing. We compare I−V characteristics of single-dot and double-dot systems and show that for a given measured I−V curve, considering the possibility of a second dot is equivalent to decreasing the fit temperature. Thus, our method allows one to gain information about the structure of an experimental system based on an I−V measurement.