Why is liquid hydrogen useful for producing very low laboratory temperatures?

Liquid hydrogen is useful for producing very low laboratory temperatures because of its extremely low boiling point of −252.77 °C.1

In the field of cryogenics, the ability to reach and maintain such extreme temperatures is essential for studying low-temperature phenomena. Hydrogen gas itself is liquefied by utilizing the cooling effect that occurs when the gas is allowed to expand at temperatures below −68.6 °C, a process that becomes increasingly pronounced at temperatures below that of liquid nitrogen.1

By providing a medium at these near-absolute-zero conditions, liquid hydrogen enables researchers to investigate the unique properties of materials that emerge only at cryogenic temperatures, such as changes in thermal conductivity and electrical resistance.12