Controlling quantum interference near avoided energy-level crossings is crucial for fast and reliable coherent manipulation in quantum information processing. However, achieving tunable quantum interference in atomically-precise engineered structures remains challenging. Here, we demonstrate electrical control of quantum interference using atomic spins on an insulating film in a scanning tunneling microscope. Using bias voltages applied across the tunnel junction, we modulate the atomically-confined magnetic interaction between the probe tip and surface atoms with a strong electric field, and drive the spin state rapidly through the energy-level anticrossing. This all-electrical manipulation allows us to achieve Landau-Zener-St\"uckelberg-Majorana (LZSM) interferometry on both single spins and pairs of interacting spins. The LZSM pattern exhibits multiphoton resonances, and its asymmetry suggests that the spin dynamics is influenced by spin-transfer torque of tunneling electrons. Multi-level LZSM spectra measured on coupled spins with tunable interactions show distinct interference patterns depending on their many-body energy landscapes. These results open new avenues for all-electrical quantum manipulation in spin-based quantum processors in the strongly driven regime.
@article{arxiv.2506.01033,
title = {Electrically tunable quantum interference of atomic spins on surfaces},
author = {Hao Wang and Jing Chen and Peng Fan and Yelko del Castillo and Alejandro Ferrón and Lili Jiang and Zilong Wu and Shijie Li and Hong-Jun Gao and Heng Fan and Joaquín Fernández-Rossier and Kai Yang},
journal= {arXiv preprint arXiv:2506.01033},
year = {2025}
}