Recently,the Kochen–Specker theorem has been demonstrated and quantum contextuality has been observed experimentally by using special and independent quantum states.On the other hand,recent investigations have shown that a thermal light source can mimic the two-photon entangled source to perform the imaging effects.We perform an all-or-nothing–type Kochen-Specker experiment using the thermal light source and obtain the same results as those using quantum sources.The physical origin for such a phenomenon is analyzed.
An Autler-Townes（AT） spectroscopy based on phase conjugate six-wave mixing（SWM） is proposed to detect AT doublet of high-lying state in a Doppler-broadened cascade four-level system.It is found that the SWM spectrum is dependent strongly on the ratios between the magnitudes of the wave vectors.We discuss how the Doppler broadening affects the SWM spectrum from a time-domain viewpoint and find that,due the atomic motion,the atomic polarizations acquire different phases for atoms with different velocities as time evolves.The Doppler free SWM spectrum can be obtained only when the atomic polarization can be rephasing again at certain time after the interactions of all the incident fields.
