Transport spectroscopy of two-spin states in a double quantum dot can be performed by an AC electric field which tunes the energy detuning. However, a problem arises when the transition rate between the states is small and, consequently, the AC-induced current is suppressed. Here, we show that if the AC field tunes the inter-dot tunnel barrier then for large detuning the transition rate increases drastically resulting in high current. Multi-photon resonances are enhanced by orders of magnitude. Our study demonstrates an efficient way for fast two-spin transitions.
@article{arxiv.1902.01979,
title = {Spectroscopy of double quantum dot two-spin states by tuning the inter-dot barrier},
author = {G. Giavaras and Y. Tokura},
journal= {arXiv preprint arXiv:1902.01979},
year = {2019}
}