  This thesis is focused on the design and analysis of quantum communication
protocols. Several schemes for quantum communication have been introduced in
the recent past. For example, quantum teleportation, dense coding, quantum key
distribution, quantum secure direct communication, etc., have been rigorously
studied in the last 2-3 decades. Specifically, a specific attention of the
present thesis is to study the quantum teleportation schemes with entangled
orthogonal and nonorthogonal states and their experimental realization, but not
limited to it. We have also studied some aspects of quantum cryptography.
