We present the first results of a survey for high redshift , z \geq 6 , quasars using izY multi-colour photometric observations from the Dark Energy Survey ( DES ) .
Here we report the discovery and spectroscopic confirmation of the z _ { AB } ,Y _ { AB } = 20.2 , 20.2 ( M _ { 1450 } = - 26.5 ) quasar DES J0454 - 4448 with a redshift of z = 6.09 \pm 0.02 based on the onset of the Lyman- \alpha forest and a HI near zone size of 4.1 _ { -1.2 } ^ { +1.1 } proper Mpc .
The quasar was selected as an i-band drop out with i - z = 2.46 and z _ { AB } < 21.5 from an area of \sim 300 deg ^ { 2 } .
It is the brightest of our 43 candidates and was identified for spectroscopic follow-up solely based on the DES i - z and z - Y colours .
The quasar is detected by WISE and has W 1 _ { AB } = 19.68 .
The discovery of one spectroscopically confirmed quasar with 5.7 < z < 6.5 and z _ { AB } \leq 20.2 is consistent with recent determinations of the luminosity function at z \sim 6 .
DES when completed will have imaged \sim 5000 deg ^ { 2 } to Y _ { AB } = 23.0 ( 5 \sigma point source ) and we expect to discover 50-100 new quasars with z > 6 including 3-10 with z > 7 dramatically increasing the numbers of quasars currently known that are suitable for detailed studies .