Detecting axionlike dark matter with linearly polarized pulsar light

QCD axions or axionlike particles are among the most popular candidates for cold dark matter (DM) in the Universe. We proposed to detect axionlike DM, using linearly polarized pulsar light as a probe. Because of birefringence effect potentially caused by an oscillating galactic axion DM background, when pulsar light travels across the Galaxy, its linear polarization angle may vary with time. With a soliton + NFW galactic DM halo profile, we show that this strategy can potentially probe an axion-photon coupling as small as similar to 10(-13) GeV-1 for axion mass m(a) similar to 10(-22) -10(-20) eV, given the current measurement accuracy. An exclusion limit stronger than CAST (similar to 40(-10) GeV-1) and SN1987A (similar to 10(-11) GeV-1) could be extended up to m(a) similar to 10(-18) eV and similar to 10(-19) eV, respectively.