  A non-Gaussian state being a mixture of the vacuum and single-photon states
can be generated by truncating a thermal state in a quantum scissors device of
Pegg et al. [Phys. Rev. Lett. 81 (1998) 1604]. In contrast to the thermal
state, the generated state shows nonclassical property including the negativity
of Wigner function. Besides, signal amplification and signal-to-noise ratio
enhancement can be achieved.
