First quantum voltage demonstration chip, 1984. This quantum voltage chip was developed by the National Institute of Standards and Technology (NIST) and its German counterpart, Physikalisch-Technische Bundesanstalt (PTB). The 1-volt chip has 1474 Josephson junctions made of lead-indium-gold alloy electrodes. This array is not fully practical, because it often switches spontaneously between voltage levels, and the junctions cannot be thermally cycled, which occurs when the chip is taken in and out of liquid helium at 4 degrees Kelvin. Photographed at the Physical Measurement Laboratory (PML) of the NIST.