  We considered one-dimensional quantum chains of two-level Fermi particles
coupled via the tunneling driven both by ac and dc fields in the regimes of
strong and ultrastrong coupling. The frequency of ac field is matched with the
frequency of the quantum transition. Based on the fundamental principles of
electrodynamics and quantum theory, we developed a general model of quantum
dynamics for such interactions. We showed that the joint action of ac and dc
fields leads to the strong mutual influence of Rabi- and Bloch oscillations one
to another. We focused on the regime of ultrastrong coupling, for which Bloch-
and Rabi-frequencies are a significant values of the frequency of interband
transition. The Hamiltonian was solved numerically with account of
anti-resonant terms. It manifests by the appearance of great number of narrow
high-amplitude resonant lines in the spectra of tunneling current and dipole
moment. We proposed the new concept of THz spectroscopy promising for different
applications in future nanoelectronics and nano-photonics.
