Practical scheme for quantum dense coding between three parties using microwave radiation in trapped ions

We propose a practical scheme for implementing two-dimension quantum dense
coding (QDC) between three parties through manipulating three ions confined in
microtraps addressed by microwaves and assisted by a magnetic field gradient.
The ions in our scheme are not required to be strictly cooled to the
vibrational ground state because single-qubit and multi-qubit operations are
made via Ising terms, in which the vibrational modes of the ions remain
unchanged throughout the scheme, rendering our scheme robust to the heating of
the ions. We also present the detailed steps and parameters for implementing
the three-party QDC experimentally and show that the proposed scheme is within
the current techniques of ion-trap experiments.