Quantum tunneling has driven considerable advances in theoretical physics, the proliferation of quantum devices, and the development of information technologies. However, the dependence of electron tunneling behavior on the dielectric medium within the tunneling region remains controversial. To this end, a theoretical model for tuning quantum tunneling barrier height through dielectric dependence was established, which comprises the effects of interface dipole, image potential, and external stimuli. Notably, the model revealed a negative exponential relationship between barrier height and dielectric constant. This finding was further experimentally evidenced by using an Au atomic quantum tunneling probe featuring a sub-3 nm gap across different dielectric media. Furthermore, the dynamic control of barrier height was achieved through ultrasound-induced dielectric modulation within the tunneling region. These findings open new avenues for the development of broadband acoustic quantum devices and enable atomic-scale imaging within opaque and biological materials.
Tian et al. (Thu,) studied this question.