An Aharonov-Bohm (AB) sensor is provided. The AB sensor includes a beam splitter configured to split a first electron beam into a first wave and a second wave. The beam splitter is configured to direct the first wave along a first path through a field-free cage. A phase of the first wave is configured to shift in response to a vector potential of a signal. The vector potential is present within the field-free cage. The AB sensor includes a beam combiner configured to combine the phase shifted first wave with the second wave to generate a second electron beam, which is modulated based on the phase shift of the first wave. The AB sensor includes a detector configured to receive the second electron beam and to detect the signal based on the modulation of the second electron beam.