Cut-off rate analysis of practical quantum receivers

Abstract

Quantum communication with binary nonorthogonal pure states and single-shot measurements are discussed in terms of reliability function and cut-off rate. It is shown that some of different measurement strategies simultaneously attain the maximum single-shot cut-off rate. We also apply these measurements to the BPSK optical coherent states and compare them with the homodyne detection. Numerical results show that even including realistic imperfections, it is possible to exceed the homodyne limited cut-off rate.

Keywords:

• reliability function
• cut-off rate
• minimum error discrimination
• unambiguous state discrimination
• BPSK coherent signal

Notes

Note

1. In principle, one can also consider to use full information of continuous homodyne outcomes x 5. However, it often meets technical difficulties in practice, such as a limit of the resolution in real measurements, finite size of the memory for decoding, etc.