We report the first results of a high-redshift (z>~5) quasar survey using the Dark Energy Spectroscopic Instrument (DESI). As a DESI secondary target program, this survey is designed to carry out a systematic search and investigation of quasars at 4.8=5, more than one-third of existing quasars previously published at this redshift. The observations so far result in an average success rate of 23% at z>4.7. The current spectral data set has already allowed analysis of interesting individual objects (e.g., quasars with damped Ly{alpha} absorbers and broad absorption line features), and statistical analysis will follow the survey's completion. A set of science projects will be carried out leveraging this program, including quasar luminosity function, quasar clustering, intergalactic medium, quasar spectral properties, intervening absorbers, and properties of early supermassive black holes. Additionally, a sample of 38 new quasars at z~3.8-5.7 discovered from a pilot survey in the DESI SV1 is also published in this paper.

The selected z~4.8-6.8 quasar candidates are mainly observed as dark-time targets in the Dark Energy Spectroscopic Instrument (DESI) main survey, which started on 2021-May-14. A minor part (1.6%) of candidates were observed during the DESI 1% survey (SV3; in 2021 April) and the DESI SV1 (before 2021 April 4; for 27 targets overlapped with the SV1 selection).

Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033

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