Observation of quantum interference in single–molecule junctions via electrochemical gating

Quantum interference effects arising from phase differences in coherent electron wavefunctions offer novel strategies for regulating electron transport of single molecules, and the experimental observation of quantum interference effects has persisted as a major research frontier in molecular electronics . Recent advances using electrochemical gating have achieved the experimental evidences of three fundamental quantum interference phenomena, including Breit-Wigner resonance, Mach-Zehnder interferometery and Fano resonance, at the room temperature , thereby completing the experimental verification of all known quantum interference effects at the single–molecule scale. This review summarizes the applications of electrochemical gating in electron coherent tunneling, discusses the experimental validation of quantum interference effects at the single–molecule scale, and prospects their potential applications in high-performance single-molecule transistor devices. • Electrochemical gating can efficiently modulate the electron tunneling barrier. • Conductance trend in non-Faradaic region aligns with the electron transmission curve. • Transmission spectral profiles of QI effects can be mapped by electrochemical gating.