Dipole Charge Detection: Toward the Readout of Bistable Charge States in Molecular QCA
Mohammad Istiaque Rahaman, Gergo P. Szakmany, Alexei O. Orlov, Gregory L. Snider · IEEE Sensors Letters · 2023
Molecular electronics is one of the revolutionary platforms to perform computation. In molecular quantum-dot cellular automata (mQCA), binary information can be encoded in candidate molecules by single charge localization, and logic operation is performed by using electrostatic interactions among neighboring cells. However, charge detection at the molecular level is extremely challenging. In this letter, we have fabricated two isolated sub-20-nm metal dots interconnected by a tunnel barrier that mimics an mQCA cell. Using a novel charge cancelation scheme, we observe robust detection of electron switching in the double-dot structure by a single-electron transistor at a temperature of 2.7 K. The experimentally observed period of single-electron charging in the double dots is in good correlation with COMSOL multiphysics’ simulations.