London Centre for Nanotechnology, University College London, London, United Kingdom, Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama, Japan, B. Verkin Institute for Low Temperature Physics and Engineering, Kharkov, Ukraine, V. Kazarin Kharkov National University, Kharkov, Ukraine, CEA/LETI-MINATEC, CEA-Grenoble, Grenoble, France, Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge, United Kingdom, Donostia International Physics Center, Donostia-San Sebastian, Spain, Department of Material Physics, Universidad Del Pais Vasco, UPV/EHU, San Sebastian, Spain, Physics Department, University of Michigan, Ann Arbor, MI, United States, Department of Electronic and Electrical Engineering, University College London, London, United Kingdom

We study Landau-Zener-Stückelberg-Majorana (LZSM) interferometry under the influence of projective readout using a charge qubit tunnel-coupled to a fermionic sea. This allows us to characterize the coherent charge-qubit dynamics in the strong-driving regime. The device is realized within a silicon complementary metal-oxide-semiconductor (CMOS) transistor. We first read out the charge state of the system in a continuous nondemolition manner by measuring the dispersive response of a high-frequency electrical resonator coupled to the quantum system via the gate. By performing multiple fast passages around the qubit avoided crossing, we observe a multipassage LZSM interferometry pattern. At larger driving amplitudes, a projective measurement to an even-parity charge state is realized, showing a strong enhancement of the dispersive readout signal. At even larger driving amplitudes, two projective measurements are realized within the coherent evolution resulting in the disappearance of the interference pattern. Our results demonstrate a way to increase the state readout signal of coherent quantum systems and replicate single-electron analogs of optical interferometry within a CMOS transistor. © 2018 American Physical Society.