Bell tests for continuous-variable systems using hybrid measurements and heralded amplifiers

Abstract

We present Bell tests for optical continuous-variable systems, combining both hybrid measurements (i.e., measuring both particle and wave aspects of light) and heralded amplifiers. We discuss two types of schemes, in which the amplifier is located either at the source or at the parties' laboratories. The inclusion of amplifiers helps to reduce the detrimental effect of losses in the setup. In particular, we show that the requirements for a loophole-free Bell test in terms of detection efficiency and transmission losses are significantly reduced, approaching the experimentally accessible regime. © 2012 American Physical Society.