Toward flying qubit spectroscopy

摘要

While the coherent control of two-level quantum systems, qubits, is now standard, their continuum electronic equivalents, flying qubits, are much less developed. The first step in this direction has been achieved in dc interferometry experiments. Here, we propose a simple setup to perform the second step, the spectroscopy of these flying qubits, by measuring the dc response to a high-frequency ac voltage drive. Using two different concurring approaches (Floquet theory and time-dependent simulations) and three different models (an analytical model, a simple microscopic model, and a realistic microscopic model), we predict the power-frequency map of the multiterminal device. We argue that this spectroscopy provides a direct measurement of the flying qubit characteristic frequencies and a key validation for more advanced quantum manipulations.