Time-Domain Spectroscopy of Mesoscopic Conductors Using Voltage Pulses

The development of single-electron sources is paving the way for a novel type of experiment in which individual electrons are emitted into a quantum-coherent circuit. However, to facilitate further progress toward fully coherent on-chip experiments with electrons, a detailed understanding of the quantum circuits is needed. Here, it is proposed to perform time-domain spectroscopy of mesoscopic conductors by applying Lorentzian-shaped voltage pulses to an input contact. Specifically, it is shown how characteristic timescales of a quantum-coherent conductor can be extracted from the distribution of waiting times between charge pulses propagating through the circuit. To illustrate the idea, Floquet scattering theory is employed to evaluate the electron waiting times for an electronic Fabry–Pérot cavity and a Mach–Zehnder interferometer. The perspectives for an experimental realization of the proposal are discussed and possible avenues for further developments are identified.