The nonclassicality of photon-added coherent fields in the thermal channel is investigated by exploring the volume of the negative part of the Wigner function that reduces with the dissipative time. The Wigner functions become positive when the decay time exceeds a threshold value. For the case of the single photon-added coherent state, we derive the exact threshold values of decay time in the thermal channel. For arbitrary partial negative Wigner distribution function, a generic analytical relation between the mean photon number of heat bath and the threshold value of decay time is presented. Finally, the possible application of single photon-added coherent states in quantum computation has been briefly discussed.
© 2008 Optical Society of America
Original Manuscript: February 21, 2007
Revised Manuscript: August 6, 2007
Manuscript Accepted: September 24, 2007
Published: December 20, 2007
Shang-Bin Li, Justin Liu, Xu-Bo Zou, and Guang-Can Guo, "Nonclassicality of quantum excitation of classical coherent fields in thermal environments," J. Opt. Soc. Am. B 25, 54-59 (2008)