Probing Dark Matter Halos of High-redshift Quasars via Wide-Field Clustering

High-redshift quasars are powerful tracers of both astrophysical processes and large-scale structure in the early Universe. Using a sample of 1,251 spectroscopically confirmed quasars and 827 highly reliable photometric quasar candidates selected with a machine-learning framework, all at 4.7 at most z < 6.3 (excluding 5.4 < z < 5.6) and with a median luminosity of M 1450 about-25.5, we investigate the large-scale environments of quasars near the end of cosmic reionization. We measure the projected auto-correlation function of the quasar population and derive bias parameters of b=22.11+2.17-2.19 and 28.55+5.76-5.75 for the redshift intervals 4.7 at most z<5.4 and 5.6 at most z<6.3, respectively. These correspond to characteristic dark matter halo masses of (M h/M)=12.66+0.10-0.11 and 12.62+0.21-0.21, respectively. We further estimate quasar duty cycles of 0.011+0.017-0.007 and 0.012+0.104-0.011 for the two redshift bins. These measurements are consistent with previous studies and the observed f duty -- M halo relation, indicating that only a small fraction of suitable dark matter halos host optically luminous quasars at any given time. The inferred low duty cycles suggest that a substantial fraction of supermassive black hole growth may occur during obscured accretion phases. Our results provide new constraints on the connection between high-redshift quasars and their host dark matter halos, offering valuable insights into the co-evolution of supermassive black holes and large-scale structure in the early Universe.