Generation of optical `Schrödinger cats' from photon number states

摘要: Schrodinger's cat is a Gedankenexperiment in quantum physics, which an atomic decay triggers the death of cat. Because physics allow atoms to remain superpositions states, classical would then be simultaneously dead and alive. By analogy, 'cat' state freely propagating light can defined as superposition well separated quasi-classical states-it wave that possesses two opposite phases. Such states play important role fundamental tests theory many information processing tasks, including computation, teleportation precision measurements. Recently, optical Schrodinger 'kittens' were prepared; however, they are too small for most aforementioned applications increasing their size experimentally challenging. Here we demonstrate, theoretically experimentally, protocol allows generation arbitrarily large squeezed using homodyne detection photon number resources. We implemented this with pulses containing photons, producing negative Wigner function. This clearly exhibits several phase-space interference fringes between 'dead' 'alive' components, enough become useful experimental theory.