LAUSR

Abstract Entangled states play an important role in quantum computation and quantum information processing. Beam splitter, a linear device, is often used to prepare entangled states and quantum mechanics representations. For any two input states, the formula for the fidelity is derived, including the Q function representation, the P function representation, and the Wigner function representation, by using the output states from beam splitter as a source of quantum teleportation. This provides a new way to calculate the fidelity. As applications, two single-mode squeezed vacuum states and coherent superposition state together with coherent state are used as inputs, and the fidelity for teleporting coherent state is discussed. Our method provide more alternatives for calculating fidelity of teleportaion.