  As quantum computers become real, it is high time we come up with effective
techniques that help programmers write correct quantum programs. In classical
computing, formal verification and sound static type systems prevent several
classes of bugs from being introduced. There is a need for similar techniques
in the quantum regime. Inspired by Hoare Type Theory in the classical paradigm,
we propose Quantum Hoare Types by extending the Quantum IO Monad by indexing it
with pre- and post-conditions that serve as program specifications. In this
paper, we introduce Quantum Hoare Type Theory (QHTT), present its syntax and
typing rules, and demonstrate its effectiveness with the help of examples.
  QHTT has the potential to be a unified system for programming, specifying,
and reasoning about quantum programs. This is a work in progress.
