  The current focus of academia and the telecommunications industry has been
shifted to the development of the six-generation (6G) cellular technology, also
formally referred to as IMT-2030. Unprecedented applications that 6G aims to
accommodate demand extreme communications performance and, in addition,
disruptive capabilities such as network sensing. Recently, there has been a
surge of interest in terahertz (THz) frequencies as it offers not only massive
spectral resources for communication but also distinct advantages in sensing,
positioning, and imaging. The aim of this paper is to provide a brief outlook
on opportunities opened by this under-exploited band and challenges that must
be addressed to materialize the potential of THz-based communications and
sensing in 6G systems.
