Techniques for high fidelity quantum teleportation include receiving an
input photon representing a qubit. Ancilla photons are generated in a particular
ancilla quantum state chosen to reduce a rate of error below a threshold error
rate. The ancilla and the input photon are combined to populate output channels.
A number of photons representing logical value 1 are measured in a subset of the
output channels. A particular output channel is determined based on the measured
number of photons. A teleported photon is obtained at the particular output channel
with an error rate below the threshold error rate. These techniques allow the ancilla
quantum state to be chosen to minimize the error despite the presence of losses
and noise. Quantum logic operations are performed by teleporting two input qubits
with the quantum state of the ancilla chosen to produce the desired logical result
and reduce the error.