All-Zero Tunneling Rates in an Ultra-Dense Waveguide Array

Quantum tunneling, a well-known phenomenon in finite deep potential wells, serves as the foundation for constructing scanning tunneling microscopes and tunneling diodes. While this phenomenon has proven valuable in integrated devices, it can pose challenges, introducing leakage current in electronic devices or unwanted crosstalk in optical counterparts. Current solutions effectively mitigate tunneling effects to the nearest neighbors; however, addressing tunneling to the 2^nd and 3^rd nearest neighbors remains an unresolved challenge in the context of multi-quantum-well systems. This study focuses on exploring periodic multi-quantum-well structures, aiming to uncover the possibility of achieving all-zero tunneling rates (AZTR) through a square wave periodic drive. This discovery utilizing an on-chip optical system is experimentally validated as an analogy. The results unequivocally demonstrate that the approach significantly enhances optical confinement compared to configurations with non-all-zero tunneling rates (NAZTR). This breakthrough not only introduces a novel method for suppressing tunneling in multi-quantum-well systems but also provides valuable insights into understanding tunneling behavior in quantum systems, holding promise for enhancing the integration density of on-chip electronic and photonic systems.