A silicon-based single-electron interferometer coupled to a fermionic sea

Abstract

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 evenparity 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.

Fast, High-Fidelity Conditional-Phase Gate Exploiting Leakage Interference in Weakly Anharmonic Superconducting Qubits

“…This fringe can be understood as "leakage interference" between j11i and j02i by analogy to a Mach-Zehnder interferometer [34]. Such analogy has been exploited in a variety of platforms [39][40][41][42]46] to demonstrate coherent control of a single qubit by showing Stückelberg oscillations [38] as a consequence of periodic driving of the qubit into an avoided crossing. Here we pulse in-and-out of j11i ↔ j02i twice to realize low-leakage two-qubit gates.…”

Time-Domain Grating with a Periodically Driven Qutrit

“…A modulated physical system may exhibit quite different dynamics from its free evolution 1 , such as the dynamical phase transition occurring in modulated systems [2][3][4] , decoherence suppression of a qubit dynamically decoupled from its environment [5][6][7] , and Landau-Zener-Stuckelberg interference in modulated two and three-level systems [8][9][10][11][12] . With the advancement of control technologies, the modulation of a physical system has great potential not only in designing novel quantum phenomena [13][14][15][16][17] but also in deepening the understanding of the physics.…”

Low-frequency spectroscopy for quantum multilevel systems

“…[16][17][18][19][20][21][22], while other examples of driven multi-level systems, where LZSM physics is relevant, are Refs. [10,[23][24][25][26][27][28][29][30][31][32].…”