Current-to-Voltage Conversion with Integrated Quantum Hall Resistors

We report on current-to-voltage conversion with an invariant 1 M Ω quantized Hall array resistance. In a series connection of a battery-operated Zener voltage reference, a stable 1 M Ω combination resistance reference, and the 1 M Ω Hall array, the input current in the circuit and the current through the array are determined by a potentiometric method. The above two currents coincide with each other down to the relative measurement uncertainty of a part in 10
⁷
at 1 μA. This simple experiment shows that calibration-free precision current measurement, directly linked to the Planck constant h and the elementary charge e, can be performed by a Hall array combined with a Josephson effect-based quantum voltmeter.